Physics · JEE Main, NEET, Olympiad (NSEP)

Magnetic Effects & Magnetism

276 practice questions with a worked solution for each. Tap an option to see instantly if you are right.

224MCQ52Numerical66With diagram
Start with question 1
  1. 1The magnetic field at the centre of a circular coil of radius RR carrying current II is B0B_0. At an axial point at distance x=R3x = R\sqrt{3} from the centre, the magnetic field is:JEE Main/MCQ/Medium
  2. 2The magnetic susceptibility of a diamagnetic substance is:NEET/MCQ/Medium
  3. 3A coaxial cable consists of an inner solid wire of radius aa and an outer thin cylindrical shell of radius bb carrying equal and opposite steady current II. The magnetic energy stored per unit length in the space between aa and bb is:Olympiad (NSEP)/MCQ/Hard/With diagram
  4. 4The ratio of magnetic field at the centre of a current carrying coil of radius rr to the magnetic field at distance rr from the centre of coil on its axis is x:1\sqrt{x}:1. The value of xx is _____.JEE Main/Numerical/Medium/Biot-Savart's Law and Ampere's Circuital Law
  5. 5Two identical circular wires of radius 20cm20cm and carrying current 2A\sqrt{2}A are placed in perpendicular planes as shown in figure. The net magnetic field at the centre of the circular wires is________\times {10}^{-8}T.

    (Take     π=3.14\pi =3.14)    JEE Main/Numerical/Medium/Biot-Savart's Law and Ampere's Circuital Law/With diagram
  6. 6A rod with circular cross-section area 2cm22{cm}^{2} and length 40cm40cm is wound uniformly with 400400 turns of an insulated wire. If a current of 0.4A0.4A flows in the wire windings, the total magnetic flux produced inside windings is 4π×10−6Wb4\pi \times {10}^{-6}Wb. The relative permeability of the rod is
    (Given : Permeability of vacuum     μ0=4π×10−7NA−2{\mu }_{0}=4\pi \times {10}^{-7}N{A}^{-2})    JEE Main/MCQ/Medium/Biot-Savart's Law and Ampere's Circuital Law
  7. 7A closely wounded circular coil of radius 5cm5cm produces a magnetic field of 37.68×10−4T37.68\times {10}^{-4}T at its center. The current through the coil is _____ AA. [Given, number of turns in the coil is 100100 and π=3.14\pi =3.14]JEE Main/Numerical/Medium/Biot-Savart's Law and Ampere's Circuital Law
  8. 8A current of 1.5A1.5A is flowing through a triangle, of side 9cm9cm each. The magnetic field at the centroid of the triangle is :
    (Assume that the current is flowing in the clockwise direction.)    JEE Main/MCQ/Medium/Biot-Savart's Law and Ampere's Circuital Law
  9. 9A coil having NN turns is wound tightly in the form of a spiral with inner and outer radii aa and bb respectively. Find the magnetic field at centre, when a current II passes through coil :JEE Main/MCQ/Medium/Biot-Savart's Law and Ampere's Circuital Law
  10. 10A long, straight Wire of radius a carries a current distributed uniformly over its cross-section. The ratio of the magnetic fields due to the wire at distance a3\dfrac{a}{3} and 2a2a , respectively from the axis of the wire is:JEE Main/MCQ/Medium/Biot-Savart's Law and Ampere's Circuital Law
  11. 11A current loop, having two circular arcs joined by two radial lines is shown in the figure. It carries a current of 10A.10A. The magnetic field at point OO will be close to:

    JEE Main/MCQ/Medium/Biot-Savart's Law and Ampere's Circuital Law/With diagram
  12. 12A charge QQ is uniformly distributed over the surface of non conducting disc of radius RR. The disc rotates about an axis perpendicular to its plane and passing through its centre with an angular velocity ω\omega. As a result of this rotation a magnetic field of induction BB is obtained at the centre of the disc. If we keep both the amount of charge placed on the disc and its angular velocity to be constant and vary the radius of the disc then the variation of the magnetic induction at the centre of the disc will be represented by the figureJEE Main/MCQ/Medium/Biot-Savart's Law and Ampere's Circuital Law
  13. 13A current I flows in an infinitely long wire with cross section in the form of a semicircular ring of radius R\mathrm{R}. The magnitude of the magnetic induction along its axis isJEE Main/MCQ/Medium/Biot-Savart's Law and Ampere's Circuital Law
  14. 14The magnitude of the magnetic field (B)(B) due to loop ABCDA B C D at the origin (O)(O) isJEE Main/MCQ/Medium/Biot-Savart's Law and Ampere's Circuital Law
  15. 15Wires 1 and 2 carrying currents i1i_1 and i2i_2 respectively are inclined at an angle θ\theta to each other. What is the force on a small element dl of wire 2 at a distance of r\mathrm{r} from wire 1 (as shown in the figure) due to the magnetic field of wire 1 ?
    JEE Main/MCQ/Medium/Biot-Savart's Law and Ampere's Circuital Law/With diagram
  16. 16A current of 3030 A each flows in opposite directions in two conducting wires, placed parallel to each other at a distance of 88 cm. The magnetic field at the mid point between the two wires is __________ μ\muT. (μ04π=10−7 N/A2)\left(\dfrac{\mu_0}{4\pi} = 10^{-7}\text{ N/A}^2\right)JEE Main/MCQ/Medium/Magnetic Field
  17. 17A small cube of side 11 mm is placed at the centre of a circular loop of radius 1010 cm carrying a current of 22 A. The magnetic energy stored inside the cube is α×10−14\alpha \times 10^{-14} J. The value of α\alpha is _______. (μo=4π×10−7\mu_o = 4\pi \times 10^{-7} Tm/A, π=3.14\pi = 3.14)JEE Main/MCQ/Medium/Magnetic Field
  18. 18A long cylindrical conductor with large cross section carries an electric current distributed uniformly over its cross-section. Magnetic field due to this current is :
    A. maximum at either ends of the conductor and minimum at the midpoint
    B. maximum at the axis of the conductor
    C. minimum at the surface of the conductor
    D. minimum at the axis of the conductor
    E. same at all points in the cross-section of the conductor
    Choose the correct answer from the options given below :    JEE Main/MCQ/Medium/Magnetic Field
  19. 19The magnetic field at the centre of a current carrying circular loop of radius RR is 16μ T16 \mu \mathrm{~T}. The magnetic field at a distance x=3Rx=\sqrt{3} R on its axis from the centre is ____\_\_\_\_ μT\mu \mathrm{T}.JEE Main/MCQ/Medium/Magnetic Field
  20. 20
    Two identical circular loops     PP and QQ each of radius rr are lying in parallel planes such that they have common axis. The current through PP and QQ are II and 4I4 I respectively in clockwise direction as seen from OO. The net magnetic field at OO is:    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  21. 21The current passing through a conducting loop in the form of equilateral triangle of side 43 cm4 \sqrt{3} \mathrm{~cm} is 2 A. The magnetic field at its centroid is α×10−5 T\alpha \times 10^{-5} \mathrm{~T}. The value of α\alpha is ____\_\_\_\_.
    (Given :     μo=4π×10−7\mu_{\mathrm{o}}=4 \pi \times 10^{-7} SI units)    JEE Main/MCQ/Medium/Magnetic Field
  22. 22An infinitely long straight wire carrying current II is bent in a planer shape as shown in the diagram. The radius of the circular part is rr. The magnetic field at the centre OO of the circular loop is :
    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  23. 23Figure shows a current carrying square loop ABCD of edge length is ' aa ' lying in a plane. If the resistance of the ABCA B C part is rr and that of ADCA D C part is 2 r , then the magnitude of the resultant magnetic field at centre of the square loop is
    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  24. 24A loop ABCDA , carrying current I=12 A\mathrm{I}=12 \mathrm{~A}, is placed in a plane, consists of two semi-circular segments of radius R1=6π mR_1=6 \pi \mathrm{~m} and R2=4π m\mathrm{R}_2=4 \pi \mathrm{~m}. The magnitude of the resultant magnetic field at center O is k×10−7 T\mathrm{k} \times 10^{-7} \mathrm{~T}. The value of k is ______ (Given μ0=4π×10−7TmA−1\mu_0=4 \pi \times 10^{-7} \mathrm{Tm} \mathrm{A}^{-1})
    JEE Main/Numerical/Medium/Magnetic Field/With diagram
  25. 25Let B1B_1 be the magnitude of magnetic field at center of a circular coil of radius RR carrying current II. Let B2B_2 be the magnitude of magnetic field at an axial distance ' xx ' from the center. For x:R=3:4,B2B1x: R=3: 4, \frac{B_2}{B_1} is :JEE Main/MCQ/Medium/Magnetic Field
  26. 26The magnetic field inside a 200 turns solenoid of radius 10 cm is 2.9×10−4Tesla2.9 \times 10^{-4} \mathrm{Tesla}. If the solenoid carries a current of 0.29 A , then the length of the solenoid is ________ πcm\pi \mathrm{cm}.JEE Main/Numerical/Medium/Magnetic Field
  27. 27Consider a long straight wire of a circular cross-section (radius a) carrying a steady current I. The current is uniformly distributed across this cross-section. The distances from the centre of the wire's cross-section at which the magnetic field [inside the wire, outside the wire] is half of the maximum possible magnetic field, any where due to the wire, will beJEE Main/MCQ/Medium/Magnetic Field
  28. 28

    An infinite wire has a circular bend of radius a, and carrying a current I as shown in figure. The magnitude of magnetic field at the origin     OO of the arc is given by :    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  29. 29A long straight wire of a circular cross-section with radius ' aa ' carries a steady current II. The current I is uniformly distributed across this cross-section. The plot of magnitude of magnetic field B with distance rr from the centre of the wire is given byJEE Main/MCQ/Medium/Magnetic Field
  30. 30A current of 5A exists in a square loop of side 12 m\frac{1}{\sqrt{2}} \mathrm{~m}. Then the magnitude of the magnetic field BB at the centre of the square loop will be p×10−6 Tp \times 10^{-6} \mathrm{~T}. where, value of p is _____ .
    [\left[\right. Take μ0=4π×10−7TmA−1]\left.\mu_0=4 \pi \times 10^{-7} \mathrm{TmA}^{-1}\right].    JEE Main/Numerical/Medium/Magnetic Field
  31. 31A long straight wire of radius a carries a steady current I. The current is uniformly distributed across its cross section. The ratio of the magnetic field at a2\frac{a}{2} and 2a2 a from axis of the wire is :JEE Main/MCQ/Medium/Magnetic Field
  32. 32A solenoid of length 0.5 m0.5 \mathrm{~m} has a radius of 1 cm1 \mathrm{~cm} and is made up of ' m\mathrm{m} ' number of turns. It carries a current of 5 A5 \mathrm{~A}. If the magnitude of the magnetic field inside the solenoid is 6.28×10−3 T6.28 \times 10^{-3} \mathrm{~T} then the value of mm is _____.JEE Main/Numerical/Medium/Magnetic Field
  33. 33In a co-axial straight cable, the central conductor and the outer conductor carry equal currents in opposite directions. The magnetic field is zero :JEE Main/MCQ/Medium/Magnetic Field
  34. 34A regular polygon of 66 sides is formed by bending a wire of length 4π4\pi meter. If an electric current of 4π3A4\pi \sqrt{3}A is flowing through the sides of the polygon, the magnetic field at the centre of the polygon would be x×10−7T.x\times {10}^{-7}T. The value of xx is ______.JEE Main/Numerical/Medium/Magnetic Field
  35. 35Two circular coils PP and QQ of 100100 turns each have same radius of πcm\pi cm. The currents in PP and RR are 1A1A and 2A2A respectively. PP and QQ are placed with their planes mutually perpendicular with their centers coincide. The resultant magnetic field induction at the center of the coils is xmT\sqrt{x}mT, where x=x= ______. [Use μ0=4π×10−7TmA−1{\mu }_{0}=4\pi \times {10}^{-7}Tm{A}^{-1}]JEE Main/Numerical/Medium/Magnetic Field
  36. 36The current of 5A5A flows in a square loop of sides 1m1m is placed in air. The magnetic field at the centre of the loop is X2×10−7TX\sqrt{2}\times {10}^{-7}T. The value of XX is _________.JEE Main/Numerical/Medium/Magnetic Field
  37. 37Two insulated circular loop AA and BB radius aa carrying a current of II in the anti clockwise direction as shown in figure. The magnitude of the magnetic induction at the centre will be:JEE Main/MCQ/Medium/Magnetic Field/With diagram
  38. 38The magnetic field at the centre of a wire loop formed by two semicircular wires of radii R1=2πm{R}_{1}=2\pi m and R2=4πm{R}_{2}=4\pi m carrying current I=4AI=4A as per figure given below is α×10−7T\alpha \times {10}^{-7}T. The value of α\alpha is _____. (Centre OO is common for all segments)JEE Main/Numerical/Medium/Magnetic Field/With diagram
  39. 39Two long, straight wires carry equal currents in opposite directions as shown in figure. The separation between the wires is 5.0cm5.0cm. The magnitude of the magnetic field at a point PP midway between the wires is _____\mu T. (Given: μ0=4π×10−7TmA−1{\mu }_{0}=4\pi \times {10}^{-7}Tm{A}^{-1})JEE Main/Numerical/Medium/Magnetic Field/With diagram
  40. 40A straight wire carrying a current of 14A14A is bent into a semicircular arc of radius 2.2cm2.2cm as shown in the figure. The magnetic field produced by the current at the centre OO of the arc is ____ ×10–4T\times {10}^{–4}T
    JEE Main/Numerical/Medium/Magnetic Field/With diagram
  41. 41The magnetic intensity at the centre of a long current carrying solenoid is found to be 1.6×103Am−11.6\times {10}^{3}A{m}^{-1}. If the number of turns is 88 per cmcm, then the current flowing through the solenoid is ______A.JEE Main/Numerical/Medium/Magnetic Field
  42. 42A long straight wire of circular cross-section (radius aa) is carrying steady current I.I. The current II is uniformly distributed across this cross-section. The magnetic field isJEE Main/MCQ/Medium/Magnetic Field
  43. 43As shown in the figure, a long straight conductor with semicircular arc of radius π10m\dfrac{\pi }{10}m is carrying current I=3AI=3A. The magnitude of the magnetic field. at the center OO of the arc is: (The permeability of the vacuum =4π×10−7NA−2=4\pi \times {10}^{-7}{NA}^{-2} )
    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  44. 44A coil is placed in magnetic field such that plane of coil is perpendicular to the direction of magnetic field. The magnetic flux through a coil can be changed:
    A. By changing the magnitude of the magnetic field within the coil.
    B. By changing the area of coil within the magnetic field.
    C. By changing the angle between the direction of magnetic field and the plane of the coil.
    D. By reversing the magnetic field direction abruptly without changing its magnitude.
    Choose the most appropriate answer from the options given below:    JEE Main/MCQ/Medium/Magnetic Field
  45. 45Find the magnetic field at the point P in figure. The curved portion is a semicircle connected to two long straight wires.JEE Main/MCQ/Medium/Magnetic Field/With diagram
  46. 46A long conducting wire having a current II flowing through it, is bent into a circular coil of NN turns. Then it is bent into a circular coil of nn turns. The magnetic field is calculated at the centre of coils in both the cases. The ratio of the magnetic field in first case to that of second case is:JEE Main/MCQ/Medium/Magnetic Field
  47. 47As shown in the figure, a current of 2A2A flowing in an equilateral triangle of side 43cm4\sqrt{3}cm . The magnetic field at the centroid OO of the triangle is :

    (Neglect the effect of earth’s magnetic field)    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  48. 48The electric current in a circular coil of four turns produces a magnetic induction 32T32T at its centre. The coil is unwound and is rewound into a circular coil of single turn, the magnetic induction at the centre of the coil by the same current will be :JEE Main/MCQ/Medium/Magnetic Field
  49. 49The magnitude of magnetic induction at mid-point OO due to current arrangement as shown in figure will be
    .    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  50. 50A single current carrying loop of wire carrying current II flowing in anticlockwise direction seen from +vez+vez direction and lying in xyxy plane is shown in figure. The plot of j^\hat{j} component of magnetic field (By)(By) at a distance aa (less than radius of the coil) and on yzyz plane vszvsz coordinate looks like
    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  51. 51Two long parallel wires carrying currents 8A8A and 15A15A in opposite directions are placed at a distance of 7cm7cm from each other. A point PP is at equidistant from both the wires such that the lines joining the point PP to the wires are perpendicular to each other. The magnitude of magnetic field at PP is ______ ×10−6T\times {10}^{-6}T. (Given: 2=1.4\sqrt{2}=1.4)JEE Main/Numerical/Medium/Magnetic Field
  52. 52A solenoid of 12001200 turns is wound uniformly in a single layer on a glass tube 2m2m long and 0.2m0.2m in diameter. The magnetic intensity at the center of the solenoid when a current of 2A2A flows through it is:JEE Main/MCQ/Medium/Magnetic Field
  53. 53Match List I with List II List – I
    (Current configuration) List – II
    (Magnetic field at point     OO) A I. B0=μ0I4πr[π+2]{B}_{0}=\dfrac{{\mu }_{0}I}{4\pi r}[\pi +2] B II. B0=μ04Ir{B}_{0}=\dfrac{{\mu }_{0}}{4}\dfrac{I}{r} C III. B0=μ0I2πr[π−1]{B}_{0}=\dfrac{{\mu }_{0}I}{2\pi r}[\pi -1] D IV. B0=μ0I4πr[π+1]{B}_{0}=\dfrac{{\mu }_{0}I}{4\pi r}[\pi +1] Choose the correct answer from the option given below:    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  54. 54A long solenoid is formed by winding 7070 turns cm−1{cm}^{-1} . If 2.0A2.0A current flows, then the magnetic field produced inside the solenoid is ______________.
    (µ0=4π×10–7TmA–1)({µ}_{0}=4\pi \times {10}^{–7}Tm{A}^{–1})    JEE Main/MCQ/Medium/Magnetic Field
  55. 55A circular loop of radius RR is carrying current iAiA. The ratio of magnetic field at the centre of circular loop and at a distance RR from the center of the loop on its axis is :JEE Main/MCQ/Medium/Magnetic Field
  56. 56The magnetic field at the center of current carrying circular loop is B1{B}_{1}. The magnetic field at a distance of 3\sqrt{3} times radius of the given circular loop from the center on its axis is B2{B}_{2}. The value of B1B2\dfrac{{B}_{1}}{{B}_{2}} will beJEE Main/MCQ/Medium/Magnetic Field
  57. 57BX{B}_{X} and BY{B}_{Y} are the magnetic field at the centre of two coils of two coils XX and YY respectively, each carrying equal current. If coil XX has 200200 turns and 20cm20cm radius and coil YY has 400400 turns and 20cm20cm radius, the ratio of BX{B}_{X} and BY{B}_{Y} isJEE Main/MCQ/Medium/Magnetic Field
  58. 58The electric current in a circular coil of 22 turns produces a magnetic induction B1{B}_{1} at its centre. The coil is unwound and is rewound into a circular coil of 55 turns and the same current produces a magnetic induction B2{B}_{2} at its centre.
    The ratio of     B2B1\dfrac{{B}_{2}}{{B}_{1}} is:    JEE Main/MCQ/Medium/Magnetic Field
  59. 59Two long current carrying conductors are placed parallel to each other at a distance of 8cm8cm between them. The magnitude of magnetic field produced at mid-point between the two conductors due to current flowing in them is 300μT300\mu T. The equal current flowing in the two conductors is :JEE Main/MCQ/Medium/Magnetic Field
  60. 60An infinitely long hollow conducting cylinder with radius RR carries a uniform current along its surface.
    Choose the correct representation of magnetic field     (B)\left(B\right)as a function of radial distance (r)\left(r\right) from the axis of cylinder.    JEE Main/MCQ/Medium/Magnetic Field
  61. 61A long solenoid carrying a current produces a magnetic field BB along its axis. If the current is doubled and the number of turns per cmcm is halved, the new value of magnetic field will be equal toJEE Main/MCQ/Medium/Magnetic Field
  62. 62A long straight wire with a circular cross-section having radius RR, is carrying a steady current II. The current II is uniformly distributed across this cross-section. Then the variation of magnetic field due to current II with distance r(r<R)r\left(r\lt R\right) from its centre will beJEE Main/MCQ/Medium/Magnetic Field
  63. 63The magnetic field at the centre of a circular coil of radius rr, due to current I flowing through it, is BB. The magnetic field at a point along the axis at a distance r2\dfrac{r}{2} from the centre is :JEE Main/MCQ/Medium/Magnetic Field
  64. 64The temperature of 3.00mol3.00mol of an ideal diatomic gas is increased by 40.0∘C40.0^{\circ}C without changing the pressure of the gas. The molecules in the gas rotate but do not oscillate. If the ratio of change in internal energy of the gas to the amount of workdone by the gas is x10.\dfrac{x}{10}. Then the value of xx (round off to the nearest integer) is _________.
    (( GivenR=8.31Jmol−1K−1)\left.R=8.31J{mol}^{-1}{K}^{-1}\right)    JEE Main/Numerical/Medium/Magnetic Field
  65. 65A coaxial cable consists of an inner wire of radius aa surrounded by an outer shell of inner and outer radii bb and cc respectively. The inner wire carries an electric current i0{i}_{0} which is distributed uniformly across cross-sectional area. The outer shell carries an equal current in opposite direction and distributed uniformly. What will be the ratio of the magnetic field at a distance xx from the axis when (i)\left(i\right) x<ax\lt a and (ii)\left(ii\right) a<x<ba\lt x\lt b ?JEE Main/MCQ/Medium/Magnetic Field
  66. 66The fractional change in the magnetic field intensity at a distance rr from centre on the axis of current carrying coil of radius aa to the magnetic field intensity at the centre of the same coil is: (Take r<ar\lt a)JEE Main/MCQ/Medium/Magnetic Field
  67. 67Figure AA and BB shown two long straight wires of circular cross-section ( aa and bb with a<ba\lt b ), carrying current II which is uniformly distributed across the cross-section. The magnitude of magnetic field BB varies with radius rr and can be represented as:
    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  68. 68A loop of flexible wire of irregular shape carrying current is placed in an external magnetic field. Identify the effect of the field on the wire.JEE Main/MCQ/Medium/Magnetic Field
  69. 69Four identical long solenoids A,B,CA,B,C and DD are connected to each other as shown in the figure. If the magnetic field at the center of AA is 3T3T the field at the center of CC would be : (Assume that the magnetic field is confined with in the volume of respective solenoid).
    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  70. 70A hairpin like shape as shown in figure is made by bending a long current carrying wire. What is the magnitude of a magnetic field at point PP which lies on the centre of the semicircle ?
    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  71. 71A solenoid of 10001000 turns per metre has a core with relative permeability 500.500. Insulated windings of the solenoid carry an electric current of 5A.5A. The magnetic flux density produced by the solenoid is:
    (Permeability of free space    =4π×10−7Hm−1=4\pi \times {10}^{-7}H{m}^{-1})    JEE Main/MCQ/Medium/Magnetic Field
  72. 72Magnetic fields at two points on the axis of a circular coil at a distance of 0.05m0.05m and 0.2m0.2m from the centre are in the ratio 8:18:1. The radius of coil is _______ .JEE Main/MCQ/Medium/Magnetic Field
  73. 73A wire AA, bent in the shape of an arc of a circle, carrying a current of 2A2A and having radius 2cm2cm and another wire BB, also bent in the shape of an arc of a circle, carrying a current of 3A3A and having radius of 4cm4\text{cm}, are placed as shown in the figure. The ratio of the magnetic fields due to the wires A\text{A} and B\text{B} at the common centre O\text{O} is:
    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  74. 74Magnitude of magnetic field (in SI units) at the centre of a hexagonal shape coil of side 10cm,5010cm,50 turns and carrying currentII (Ampere) in units of μ0Iπ\dfrac{{\mu }_{0}I}{\pi } is :JEE Main/MCQ/Medium/Magnetic Field
  75. 75A very long wire ABDMNDC is shown in figure carrying current I. AB and BC parts are straight, long and at right angle. At D wire forms a circular turn DMND of radius R. AB, BC parts are tangential to circular turn at N and D. Magnetic filed at the center of circle is:
    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  76. 76A long solenoid of radius RR carries a time (t)\left(t\right) dependent current I(t)=I0t(1−t)I\left(t\right)={I}_{0}t\left(1-t\right) . A ring of radius 2R2R is placed coaxially near its middle. During the time interval 0≤t≤1,0\leq t\leq 1, the induced current (IR)\left({I}_{R}\right) and the induced EMF(VR)EMF\left({V}_{R}\right) in the ring change as:JEE Main/MCQ/Medium/Magnetic Field
  77. 77Find the magnetic field at point PP due to a straight line segment ABAB of length 6cm6cm carrying a current of 5A.5A. (See figure) (μ0=4π×10−7NA−2)\left({\mu }_{0}=4\pi \times {10}^{-7}{NA}^{-2}\right)
    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  78. 78A thin ring of 10cm10cm radius carries a uniformly distributed charge. The ring rotates at a constant angular speed of 40πrads−140\pi rad{s}^{-1} about its axis, perpendicular to its plane. Is the magnetic field its centre is 3.8×10−9T3.8\times {10}^{-9}T , then the charge carried by the ring is close to (μ0=4π×10−7N/A2).\left({\mu }_{0}=4\pi \times {10}^{-7}N/{A}^{2}\right).JEE Main/MCQ/Medium/Magnetic Field
  79. 79The magnitude of the magnetic field at the centre of an equilateral triangular loop of side 1m1m which is carrying a current of 10A10A is:

    [Take     μ0=4π×10−7NA−2{\mu }_{0}=4\pi \times {10}^{-7}N{A}^{-2} ]    JEE Main/MCQ/Medium/Magnetic Field
  80. 80A very long solenoid of radius RR is carrying current I(t)=kte−αt(k>0),I\left(t\right)=kt{e}^{-\alpha t}\left(k\gt 0\right), as a function of time (t≥0).\left(t\geq 0\right). Counterclockwise current is taken to be positive. A circular conducting coil of radius 2R2R is placed in the equitorial plane of the solenoid and concentric with the solenoid. The current induced in the outer coil is correctly depicted, as a function of time, by:JEE Main/MCQ/Medium/Magnetic Field
  81. 81Two very long, straight, and insulated wires are kept at 90o{90}^{o} angle from each other in xy−planexy-plane as shown in figure.

    These wires carry currents of equal magnitude     II , whose direction are shown in the figure. The net magnetic field at point PP will be:    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  82. 82As shown in the figure, two infinitely long, identical wires are bent by 90o{90}^{o} and placed in such a way that the segments LPLP and QMQM are along the xx - axis, while segments PSPS and QNQN are parallel to the yy - axis. If OP=OQ=4cm,OP=OQ=4cm, and the magnitude of the magnetic field at OO is 10−4T,{10}^{-4}T, and the two wires carry equal currents (see figure), the magnitude of the current in each wire and the direction of the magnetic field at OO will be (μ0=4π×10−7NA−2):\left({\mu }_{0}=4\pi \times {10}^{-7}N{A}^{-2}\right):

    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  83. 83One of the two identical conducting wires of length LL is bent in the form of a circular loop and the other one into a circular coil of NN identical turns. If the same current is passed in both, the ratio of the magnetic field at the centre of the loop (BL)\left({B}_{L}\right) to that at the centre of the coil (BC),\left({B}_{C}\right), i.e. BLBC\dfrac{{B}_{L}}{{B}_{C}} will beJEE Main/MCQ/Medium/Magnetic Field
  84. 84A current of 1 A1 \mathrm{~A} is flowing on the sides of an equilateral triangle of side 4.5×10−2 m4.5 \times 10^{-2} \mathrm{~m}. The magnetic field at the centre of the triangle will be:JEE Main/MCQ/Medium/Magnetic Field
  85. 85A Helmholtz coil has a pair of loops, each with NN turns and radius RR. They are placed coaxially at distance RR and the same current II flows through the loops in the same direction. The magnitude of the magnetic field at P,P, midway between the centres AA and C,C, is given by [Refer to figure given below]:
    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  86. 86A Helmholtz coil has pair of loops, each with NN turns and radius RR. They are placed coaxially at distance RR and the same current II flows through the loops in the same direction. The magnitude of magnetic field at PP, midway between the centres AA and CC, is given by (Refer to figure):
    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  87. 87A conducting metal circular-wire-loop of radius rr is placed perpendicular to a magnetic field which varies with time as B=B0e−tτ,B={B}_{0}{e}^{-\dfrac{t}{\tau }}, where B0andτ{B}_{0}and\tau are constants at time t=0t=0. If the resistance of the loop is RR, then the heat generated in the loop after a long time (t→∞)\left(t\rightarrow \infty \right) isJEE Main/MCQ/Medium/Magnetic Field
  88. 88Two identical wires AA and BB, each of length ll, carry the same current II . Wire AA is bent into a circle of radius RR and wire BB is bent to form a square of side aa. If BA{B}_{A} and BB{B}_{B} are the values of magnetic field at the centres of the circle and square respectively, then the ratio BABB\dfrac{{B}_{A}}{{B}_{B}} isJEE Main/MCQ/Medium/Magnetic Field
  89. 89A wire carrying current II is tied between points PP and QQ and is in the shape of a circular arc of radius RR due to a uniform magnetic field BB (perpendicular to the plane of the paper, as shown in the figure) in the vicinity of the wire. If the wire subtends an angle 2θo2{\theta }_{o} at the center of the circle (of which it forms an arch) then the tension in the wire is:
    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  90. 90Consider two thin identical conducting wires covered with very thin insulating material. One of the wires is bent into a loop and produces magnetic field B1\mathrm{B}_1, at its centre when a current I\mathrm{I} passes through it. The ratio B1:B2\mathrm{B}_1: \mathrm{B}_2 is:JEE Main/MCQ/Medium/Magnetic Field
  91. 91Three straight parallel current carrying conductors are shown in the figure. The force experienced by the middle conductor of length 25 cm25 \mathrm{~cm} is:
    JEE Main/MCQ/Medium/Magnetic Field/With diagram
  92. 92A current ii is flowing in a straight conductor of length LL. The magnetic induction at a point on its axis at a distance L4\frac{L}{4} from its centre will be :JEE Main/MCQ/Medium/Magnetic Field
  93. 93An electric current is flowing through a circular coil of radius R\mathrm{R}. The ratio of the magnetic field at the centre of the coil and that at a distance 22R2 \sqrt{2} R from the centre of the coil and on its axis is :JEE Main/MCQ/Medium/Magnetic Field
  94. 94Currents of a 10 ampere and 2 ampere are passed through two parallel thin wires AA and BB respectively in opposite directions. Wire AA is infinitely long and the length of the wire BB is 2 m2 \mathrm{~m}. The force acting on the conductor BB, which is situated at 10 cm10 \mathrm{~cm} distance from AA will beJEE Main/MCQ/Medium/Magnetic Field
  95. 95Two long parallel wires are at a distance 2 d2 \mathrm{~d} apart. They carry steady equal current flowing out of the plane of the paper as shown. The variation of the magnetic field along the line XX\mathrm{XX} ' is given byJEE Main/MCQ/Medium/Magnetic Field
  96. 96A horizontal overhead power line is at a height of 4 m4 \mathrm{~m} from the ground and carries a current of 100 A100 \mathrm{~A} from east to west. The magnetic field directly below it on the ground is (μ0=4π×10−7 T m A−1)\left(\mu_0=4 \pi \times 10^{-7} \mathrm{~T} \mathrm{~m} \mathrm{~A}^{-1}\right)JEE Main/MCQ/Medium/Magnetic Field
  97. 97Two identical conducting wires AOB\mathrm{A O B} and COD\mathrm{C O D} are placed at right angles to each other. The wire AOB\mathrm{AOB} carries an electric current I1\mathrm{I_1} and COD\mathrm{COD} carries a current I2\mathrm{I_2}. The magnetic field on a point lying at a distance ' d\mathrm{d} ' from O\mathrm{O}, in a direction perpendicular to the plane of the wires AOB\mathrm{A O B} and COD\mathrm{C O D}, will be given byJEE Main/MCQ/Medium/Magnetic Field
  98. 98A current I\mathrm{I} flows along the length of an infinitely long, straight, thin walled pipe. ThenJEE Main/MCQ/Medium/Magnetic Field
  99. 99A long straight wire of radius ' aa ' caries a steady current i\mathrm{i}. The current is uniformly distributed across its cross section. The ratio of the magnetic field at a2\frac{a}{2} and 2a2 a isJEE Main/MCQ/Medium/Magnetic Field
  100. 100A long solenoid has 200 turns per cm\mathrm{cm} and carries a current i\mathrm{i}. The magnetic field at its centre is 6.28×10−26.28 \times 10^{-2} Weber /m2/ \mathrm{m}^2. Another long solenoid has 100 turns per cm\mathrm{cm} and it carries a current i/3\mathrm{i} / 3. The value of the magnetic field at its centre isJEE Main/MCQ/Medium/Magnetic Field
  101. 101Two concentric coils each of radius equal to 2πcm2 \pi \mathrm{cm} are placed at right angles to each other. 3 Ampere and 4 ampere are the currents flowing in each coil respectively. The magnetic induction in Weber /m2/ \mathrm{m}^2 at the centre of the coils will be (μ0=4π×10−7\left(\mu_0=4 \pi \times 10^{-7}\right. Wb/A-m)JEE Main/MCQ/Medium/Magnetic Field
  102. 102The magnetic field due to a current carrying circular loop of radius 3 cm3 \mathrm{~cm} at a point on the axis at a distance of 4 cm4 \mathrm{~cm} from the centre is 54μT54 \mu \mathrm{T}. What will be its value at the centre of the Loop?JEE Main/MCQ/Medium/Magnetic Field
  103. 103A long wire carries a steady current. It is bent into a circle of one turn and the magnetic field at the centre of the coil is BB. It is then bent into a circular loop of nn turns. The magnetic field at the centre of the coil will beJEE Main/MCQ/Medium/Magnetic Field
  104. 104A current I ampere flows along an infinitely long straight thin-walled tube, then the magnetic induction at any point inside the tube isJEE Main/MCQ/Medium/Magnetic Field
  105. 105If in a circular coil AA of radius RR, current I is flowing and in another coil BB of radius 2R2 R a current 2l2 \mathrm{l} is flowing, then the ratio of the magnetic fields BA\mathrm{B}_{\mathrm{A}} and BB\mathrm{B}_{\mathrm{B}}, produced by them will beJEE Main/MCQ/Medium/Magnetic Field
  106. 106A 55 mg particle carrying a charge of 5π×10−65\pi\times 10^{-6} C is moving with velocity of (3i^+2k^)×10−2(3\hat{i}+2\hat{k})\times 10^{-2} m/s in a region having magnetic field B⃗=0.1k^\vec{B} = 0.1\hat{k} Wb/m2^2. It moves a distance of α\alpha meter along k^\hat{k} when it completes 55 revolutions. The value of α\alpha is ________.JEE Main/Numerical/Medium/Motion of Charged Particle in Magnetic Field
  107. 107The charged particle moving in a uniform magnetic field of (3i^+2j^)(3\hat{i} + 2\hat{j}) T has an acceleration (4i^−x2j^)\left(4\hat{i} - \dfrac{x}{2}\hat{j}\right) m/s2^2. The value of xx is __________.JEE Main/Numerical/Medium/Motion of Charged Particle in Magnetic Field
  108. 108A particle having charge 10−910^{-9} C moving in xx-yy plane in fields of 0.4j^0.4\hat{j} N/C and 4×10−3k^4 \times 10^{-3} \hat{k} T experiences a force of (4i^+2j^)×10−10(4\hat{i} + 2\hat{j}) \times 10^{-10} N. The velocity of the particle at that instant is _______ m/s.JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  109. 1091 μ1\,\muC charge moving with velocity v⃗=(i^−2j^+3k^)\vec{v} = \left(\hat{i} - 2\hat{j} + 3\hat{k}\right) m/s in the region of magnetic field B⃗=(2i^+3j^−5k^)\vec{B} = \left(2\hat{i} + 3\hat{j} - 5\hat{k}\right) T. The magnitude of force acting on it is α×10−6\sqrt{\alpha} \times 10^{-6} N. The value of α\alpha is _______.JEE Main/Numerical/Medium/Motion of Charged Particle in Magnetic Field
  110. 110A current carrying solenoid is placed vertically and a particle of mass mm with charge QQ is released from rest. The particle moves along the axis of solenoid. If gg is acceleration due to gravity then the acceleration (a) of the charged particle will satisfy :JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  111. 111Uniform magnetic fields of different strengths (B1\left(B_1\right. and B2B_2), both normal to the plane of the paper exist as shown in the figure. A charged particle of mass m and charge q , at the interface at an instant, moves into the region 2 with velocity vv and returns to the interface. It continues to move into region 1 and finally reaches the interface. What is the displacement of the particle during this movement along the interface?

    (Consider the velocity of the particle to be normal to the magnetic field and     B2>B1B_2 \gt B_1)    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field/With diagram
  112. 112A particle of charge qq, mass mm and kinetic energy E enters in magnetic field perpendicular to its velocity and undergoes a circular arc of radius( r). Which of the following curves represents the variation of rr with EE ?JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  113. 113A particle of charge 1.6μC1.6 \mu \mathrm{C} and mass 16μ g16 \mu \mathrm{~g} is present in a strong magnetic field of 6.28 T. The particle is then fired perpendicular to magnetic field. The time required for the particle to return to original location for the first time is ________ S. (π=3.14)(\pi=3.14)JEE Main/Numerical/Medium/Motion of Charged Particle in Magnetic Field
  114. 114Given below are two statements: one is labelled as Assertion A and the other is labelled asReason R.
    Assertion A:. If oxygen ion     (O−2)\left(\mathrm{O}^{-2}\right) and Hydrogen ion (H+)\left(\mathrm{H}^{+}\right)enter normal to the magnetic field with equal momentum, then the path of O−2\mathrm{O}^{-2} ion has a smaller curvature than that of H+\mathrm{H}^{+}.
    Reason R : A proton with same linear momentum as an electron will form a path of smaller radius of curvature on entering a uniform magnetic field perpendicularly.
    In the light of the above statements, choose the correct answer from the options given below :    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  115. 115Consider a long thin conducting wire carrying a uniform current I. A particle having mass " M " and charge " qq " is released at a distance " aa " from the wire with a speed v0v_0 along the direction of current in the wire. The particle gets attracted to the wire due to magnetic force. The particle turns round when it is at distance xx from the wire. The value of xx is [ μ0\mu_0 is vacuum permeability]JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  116. 116Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R).
    Assertion (A) : A electron in a certain region of uniform magnetic field is moving with constant velocity in a straight line path.
    Reason (R): The magnetic field in that region is along the direction of velocity of the electron. In the light of the above statements, choose the correct answer from the options given below :    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  117. 117A proton is moving undeflected in a region of crossed electric and magnetic fields at a constant speed of 2×105 ms−12 \times 10^5 \mathrm{~ms}^{-1}. When the electric field is switched off, the proton moves along a circular path of radius 2 cm . The magnitude of electric field is x×104 N/Cx \times 10^4 \mathrm{~N} / \mathrm{C}. The value of xx is _______ Take the mass of the proton =1.6×10−27 kg=1.6 \times 10^{-27} \mathrm{~kg}.JEE Main/Numerical/Medium/Motion of Charged Particle in Magnetic Field
  118. 118An electron projected perpendicular to a uniform magnetic field B moves in a circle. If Bohr's quantization is applicable, then the radius of the electronic orbit in the first excited state is :JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  119. 119A proton and a deutron ( q=+e,m=2.0u)q=+\mathrm{e}, m=2.0 \mathrm{u}) having same kinetic energies enter a region of uniform magnetic field B⃗\vec{B}, moving perpendicular to B⃗\vec{B}. The ratio of the radius rdr_d of deutron path to the radius rpr_p of the proton path is:JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  120. 120An electron with kinetic energy 5eV5 \mathrm{eV} enters a region of uniform magnetic field of 3 μT\mu \mathrm{T} perpendicular to its direction. An electric field E\mathrm{E} is applied perpendicular to the direction of velocity and magnetic field. The value of EE, so that electron moves along the same path, is _______ NC−1\mathrm{NC}^{-1}.
    (\left(\right. Given, mass of electron =9×10−31 kg=9 \times 10^{-31} \mathrm{~kg}, electric charge =1.6×10−19C)\left.=1.6 \times 10^{-19} \mathrm{C}\right)    JEE Main/Numerical/Medium/Motion of Charged Particle in Magnetic Field
  121. 121The electrostatic force (F1→)\left(\overrightarrow{F_1}\right) and magnetic force (F⃗2)\left(\vec{F}_2\right) acting on a charge qq moving with velocity vv can be written :JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  122. 122An electron is projected with uniform velocity along the axis inside a current carrying long solenoid. Then :JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  123. 123An electron moves through a uniform magnetic field B⃗=B0i^+2B0j^T\vec{B}={B}_{0}\hat{i}+2{B}_{0}\hat{j}T. At a particular instant of time, the velocity of electron is u⃗=3i^+5j^ms−1\vec{u}=3\hat{i}+5\hat{j}m{s}^{-1}. If the magnetic force acting on electron is F⃗=5ek^N\vec{F}=5e\hat{k}N, where ee is the charge of electron, then the value of B0{B}_{0} is ____ TT.JEE Main/Numerical/Medium/Motion of Charged Particle in Magnetic Field
  124. 124Two particles XX and YY having equal charges are being accelerated through the same potential difference. Thereafter, they enter normally in a region of uniform magnetic field and describes circular paths of radii R1{R}_{1} and R2{R}_{2} respectively. The mass ratio of XX and YY is :JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  125. 125A charge of 4.0μC4.0\mu C is moving with a velocity of 4.0×106ms−14.0\times {10}^{6}m{s}^{-1} along the positive yy-axis under a magnetic field BB of strength (2k^)T(2\hat{k})T. The force acting on the charge is xi^Nx\hat{i}N. The value of xx is ______.JEE Main/Numerical/Medium/Motion of Charged Particle in Magnetic Field
  126. 126A proton moving with a constant velocity passes through a region of space without any change in its velocity. If E⃗\vec{E} and B⃗\vec{B} represent the electric and magnetic fields respectively, then the region of space may have :
    (A)     E=0,B=0E=0,B=0; (B) E=0,B≠0E=0,B\neq 0; (C) E≠0,B=0E\neq 0,B=0; (D) E≠0,B≠0E\neq 0,B\neq 0
    Choose the most appropriate answer from the options given below :    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  127. 127An electron in a hydrogen atom revolves around its nucleus with a speed of 6.76×106ms–16.76\times {10}^{6}m{s}^{–1} in an orbit of radius 0.52A˚0.52Å. The magnetic field produced at the nucleus of the hydrogen atom is _______ TT.JEE Main/Numerical/Medium/Motion of Charged Particle in Magnetic Field
  128. 128An electron is moving along the positive x-axis. If uniform magnetic field is applied parallel to the negative z-axis, then
    A.The electron will experience magnetic force along positive y-axis
    B.The electron will experience magnetic force along negative y-axis
    C.The electron will not experience any force in magnetic field
    D.The electron will continue to move along the positive x-axis
    E.The electron will move along circular path in magnetic field
    Choose the correct answer from the option given below:    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  129. 129An electron is allowed to move with constant velocity along the axis of current carrying straight solenoid.
    (A) The electron will experience magnetic force along the axis of the solenoid.
    (B) The electron will not experience magnetic force.
    (C) The electron will continue to move along the axis of the solenoid.
    (D) The electron will be accelerated along the axis of the solenoid.
    (E) The electron will follow parabolic path-inside the solenoid.
    Choose the correct answer from the option given below:    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  130. 130A charge particle moving in magnetic field B,B, has the components of velocity along BB as well as perpendicular to BB. The path of the charge particle will beJEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  131. 131A proton with a kinetic energy of 2.0eV2.0eV moves into a region of uniform magnetic field of magnitude π2×10−3T\dfrac{\pi }{2}\times {10}^{-3}T. The angle between the direction of magnetic field and velocity of proton is 60o{60}^{o}. The pitch of the helical path taken by the proton is ____ cmcm. (Take, mass of proton =1.6×10−27kg=1.6\times {10}^{-27}kg and charge on proton =1.6×10−19C=1.6\times {10}^{-19}C).JEE Main/Numerical/Medium/Motion of Charged Particle in Magnetic Field
  132. 132A charge particle of 2μC2\mu C accelerated by a potential difference of 100V100V enters a region of uniform magnetic field of magnitude 4mT4mT at right angle to the direction of field. The charge particle completes semicircle of radius 3cm3cm inside magnetic field. The mass of the charge particle is ______ ×10−18kg\times {10}^{-18}kg.JEE Main/Numerical/Medium/Motion of Charged Particle in Magnetic Field
  133. 133A velocity selector consists of electric field E⃗=Ek^\vec{E}=E\hat{k} and magnetic field B⃗=Bj^\vec{B}=B\hat{j} with B=12mTB=12mT. The value EE required for an electron of energy 728eV728eV moving along the positive xx-axis to pass undeflected is
    (Given, mass of electron     =9.1×10−31kg=9.1\times {10}^{-31}kg)    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  134. 134A charge particle is moving in a uniform magnetic field (2i^+3j^)T\left(2\hat{i}+3\hat{j}\right)T. If it has an acceleration of (αi^−4j^)ms−2\left(\alpha \hat{i}-4\hat{j}\right)m{s}^{-2}, then the value of α\alpha will beJEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  135. 135Two charged particles, having same kinetic energy, are allowed to pass through a uniform magnetic field perpendicular to the direction of motion. If the ratio of radii of their circular paths is 6:56:5 and their respective masses ratio is 9:49:4. Then, the ratio of their charges will beJEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  136. 136Given below are two statements :
    Statement     II: The electric force changes the speed of the charged particle and hence changes its kinetic energy; whereas the magnetic force does not change the kinetic energy of the charged particle.
    Statement     IIII: The electric force accelerates the positively charged particle perpendicular to the direction of electric field. The magnetic force accelerates the moving charged particle along the direction of magnetic field.
    In the light of the above statements, choose the most appropriate answer from the options given below :    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  137. 137A singly ionized magnesium atom (A=24)\left(A=24\right) ion is accelerated to kinetic energy 5keV5keV, and is projected perpendicularly into a magnetic field BB of the magnitude 0.5T0.5T. The radius of path formed will be _____ cm.cm.JEE Main/Numerical/Medium/Motion of Charged Particle in Magnetic Field
  138. 138A deuteron and a proton moving with equal kinetic energy enter into to a uniform magnetic field at right angle to the field. If rd{r}_{d} and rp{r}_{p} are the radii of their circular paths respectively, then the ratio rdrp\dfrac{{r}_{d}}{{r}_{p}} will be x:1\sqrt{x}:1 where xx is _____ .JEE Main/Numerical/Medium/Motion of Charged Particle in Magnetic Field
  139. 139A metal surface is illuminated by a radiation of wavelength 4500A∘4500A^{^{\circ}}. The ejected photo-electron enters a constant magnetic field of 2mT2mT making an angle of 90∘90^{\circ} with the magnetic field. If it starts revolving in a circular path of radius 2mm2mm, the work function of the metal is approximatelyJEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  140. 140A proton and an alpha particle of the same velocity enter in a uniform magnetic field which is acting perpendicular to their direction of motion. The ratio of the radii of the circular paths described by the alpha particle and proton isJEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  141. 141A proton, a deuteron and an α\alpha-particle with same kinetic energy enter into a uniform magnetic field at right angle to magnetic field. The ratio of the radii of their respective circular paths is :JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  142. 142Given below are two statements : One is labelled as Assertion (A) and the other is labelled as Reason (R).
    Assertion (A) : In an uniform magnetic field, speed and energy remains the same for a moving charged particle.
    Reason (R): Moving charged particle experiences magnetic force perpendicular to its direction of motion.    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  143. 143Two ions of masses 4amu4amu and 16amu16amu have charges +2e+2e and +3e+3e respectively. These ions pass through the region of the constant perpendicular magnetic field. The kinetic energy of both ions is the same. Then:JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  144. 144Two ions having same mass have charges in the ratio 1:21:2. They are projected normally in a uniform magnetic field with their speeds in the ratio 2:32:3. The ratio of the radii of their circular trajectories is,JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  145. 145A deuteron and an alpha particle having equal kinetic energy enter perpendicular into a magnetic field. Let rd{r}_{d} and rα{r}_{\alpha } be their respective radii of circular path. The value of rdrα\dfrac{{r}_{d}}{{r}_{\alpha }} is equal to:JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  146. 146A proton and an α\alpha-particle, having kinetic energies Kp{K}_{p} and Kα{K}_{\alpha }, respectively, enter into a magnetic field at right angles. The ratio of the radii of the trajectory of proton to that of α\alpha -particle is 2:12:1. The ratio of Kp:Kα{K}_{p}:{K}_{\alpha } is:JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  147. 147An electron with kinetic energy K1{K}_{1} enters between parallel plates of a capacitor at an angle α\alpha with the plates. It leaves the plates at angle β\beta with kinetic energy K2.{K}_{2}. Then the ratio of kinetic energies K1:K2{K}_{1}:{K}_{2} will be :JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  148. 148An electron is moving along +x+x direction with a velocity of 6×106ms−16\times {10}^{6}{ms}^{-1}. It enters a region of uniform electric field of 300V/cm300V/cm pointing along +y+y direction. The magnitude and direction of the magnetic field set up in this region such that the electron keeps moving along the x direction will be:JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  149. 149A particle of charge qq and mass mm is moving with a velocity −vi^(v≠0)-v\hat{i}(v\neq 0) towards a large screen placed in the Y−ZY-Z plane at distance d. If there is magnetic field B⃗=B0k^,\vec{B}={B}_{0}\hat{k}, the minimum value of vv for which the particle will not hit the screen is :JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  150. 150An electron is constrained to move along the yy-axis with a speed of 0.1c0.1c (c is the speed of light) in the presence of electromagnetic wave, whose electric field is E⃗=30j^sin⁡(1.5×107t−5×10−2x)Vm−1.\vec{E}=30\hat{j}\sin \left(1.5\times {10}^{7}t-5\times {10}^{-2}x\right)V{m}^{-1}. where tt in in seconds and xx is im meters.The maximum magnetic force experienced by the electron will be: (given c=3×108ms−1c=3\times {10}^{8}m{s}^{-1} and electron charge =1.6×10−19Coloumbs=1.6\times {10}^{-19}ColoumbsJEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  151. 151A small point mass carrying some positive charge on it, is released from the edge of a table. There is a uniform electric field in this region in the horizontal direction. Which of the following options then correctly describe the trajectory of the mass ? (Curves are drawn schematically and are not to scale)JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  152. 152The figure shows a region of length 'll' with a uniform magnetic field of 0.3T0.3T in it and a proton entering the region with velocity 4×105ms−14\times {10}^{5}m{s}^{-1} making an angle 60∘60^{\circ} with the field. If the proton completes 1010 revolution by the time it cross the region shown, 'll' is close to (mass of proton =1.67×10−27kg=1.67\times {10}^{-27}kg, charge of the proton=1.6×10−19C=1.6\times {10}^{-19}C)
    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field/With diagram
  153. 153A charged particle (mass mm and charge qq) moves along XX axis with velocity V0{V}_{0}. When it passes through the origin it enters a region having uniform electric field E⃗=−Ej^\vec{E}=-E\hat{j} which extends upto x=dx=d. Equation of path of electron in the region x>dx\gt d is:
    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field/With diagram
  154. 154A beam of protons with speed 4×105ms−14\times {10}^{5}m{s}^{-1} enters a uniform magnetic field of 0.3T0.3T at an angle 60∘60^{\circ} to the magnetic field, the pitch of the resulting helical path of protons is close to : (Mass of the proton=1.67×10−27kg=1.67\times {10}^{-27}kg, charge of the proton=1.69×10−19C=1.69\times {10}^{-19}C)JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  155. 155An electron gun is placed inside a long solenoid of radius RR on its axis. The solenoid has nn turns/length and carries a current I.I. The electron gun shoots an electron along the radius of the solenoid with speed v.v. If the electron does not hit the surface of the solenoid, maximum possible value of vv is (all symbols have their standard meaning):

    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field/With diagram
  156. 156A charged particle of mass ‘ mm ’ and charge ‘ qq ’ moving under the influence of uniform electric field E⃗i^\vec{\text{E}}\hat{i} and a uniform magnetic field B⃗k^\vec{\text{B}}\hat{k} follows a trajectory from point P to Q as shown in figure. The velocities at P and Q are respectively, vi⃗v\vec{i} and −2vj⃗-2v\vec{j} . Then which of the following statements (A, B, C, D) are the correct? (Trajectory shown is schematic and not to scale)



    (A)\left(A\right) E=32(mv2qa)E=\dfrac{3}{2}\left(\dfrac{m{v}^{2}}{qa}\right)
    (B)\left(B\right) Rate of work done by the electric field at P is 32(mv3a)\dfrac{3}{2}\left(\dfrac{m{v}^{3}}{a}\right)
    (C)\left(C\right) Rate of work done by both the fields at Q is zero
    (D)\left(D\right) The difference between the magnitude of angular momentum of the particle at P and Q is 2mav2mav .    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field/With diagram
  157. 157Radiation, with wavelength 6561A˚6561Å falls on a metal surface to produce photoelectrons. The electrons are made to enter a uniform magnetic field of 3×10−4T3\times {10}^{-4}T . If the radius of the largest circular path followed by the electrons is 10mm10mm , the work function of the metal is close to:JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  158. 158An electron, moving along the x−x- axis with an initial energy of 100eV,100eV, enters a region of magnetic field B⃗=(1.5×10−3T)k^\vec{B}=\left(1.5\times {10}^{-3}T\right)\hat{k} at S (see figure). The field extends between x=0x=0 and x=2cm.x=2cm. The electron is detected at the point QQ on a screen placed 8cm8cm away from the point S.S. The distance d between PP and QQ (on the screen) is:
    (electron’s charge     1.6×10−19C1.6\times {10}^{-19}C , mass of electron =9.1×10−31kg=9.1\times {10}^{-31}kg )
    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field/With diagram
  159. 159A proton, an electron, and a Helium nucleus, have the same energy. They are in circular orbits in a plane due to magnetic field perpendicular to the plane. Let rp,re{r}_{p},{r}_{e} and rHe{r}_{He} be their respective radii, then,JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  160. 160A proton and an α\alpha- particle (with their masses in the ratio of 1:41:4 and charges in the ratio of 1:21:2 ) are accelerated from rest through a potential difference V.V. If a uniform magnetic field (B)\left(B\right) is set up perpendicular to their velocities, the ratio of the radii rp:rα{r}_{p}:{r}_{\alpha } of the circular paths described by them will be:JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  161. 161A particle of mass mm and charge qq is in an electric and magnetic field given by

    E→=2i^+3j^;B→=4j^+6k^\overrightarrow{\mathrm{E}}=2 \hat{i}+3 \hat{j} ; \overrightarrow{\mathrm{B}}=4 \hat{j}+6 \hat{k}

    The charged particle is shifted from the origin to the point     P(x=1;y=1)\mathrm{P}(x=1 ; y=1) along a straight path. The magnitude of the total work done is :    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  162. 162The region between y=0y=0 and y=dy=\mathrm{d} contains a magnetic field B→=Bz^\overrightarrow{\mathrm{B}}=\mathrm{B} \hat{\mathrm{z}}. A particle of mass m\mathrm{m} and charge q\mathrm{q} enters

    the region with a velocity     v⃗=vi^.\vec{v}=v \hat{i} . if d=mv2qB,\mathrm{d}=\frac{\mathrm{m} v}{2 \mathrm{qB}}, the acceleration of the charged particle at the point of its emergence at the other side is :    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  163. 163In an experiment, electrons are accelerated, from rest, by applying a voltage of 500 V500 \mathrm{~V}. Calculate the radius of the path if a magnetic field 100mT100 \mathrm{mT} is then applied. [Charge of the electron =1.6×10−19C=1.6 \times 10^{-19} \mathrm{C}

    Mass of the electron     =9.1×10−31 kg]\left.=9.1 \times 10^{-31} \mathrm{~kg}\right]    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  164. 164A particle having the same charge as of electron moves in a circular path of radius 0.5cm0.5cm under the influence of a magnetic field of 0.5T.0.5T. If an electric field of 100 V/m makes it to move in a straight path, then the mass of the particle is (Given charge of electron =1.6×10−19C=1.6\times {10}^{-19}C )JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  165. 165An electron, a proton and an alpha particle having the same kinetic energy are moving in circular orbits of radii re,rp,rα{r}_{e},{r}_{p},{r}_{\alpha } respectively in a uniform magnetic field B. The relation between re,rp,rα{r}_{e},{r}_{p},{r}_{\alpha } is:JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  166. 166A proton (mass mm) accelerated by a potential difference VV flies through a uniform transverse magnetic field BB. The field occupies a region of space by width dd. If α\alpha be the angle of deviation of proton from the initial direction of motion (see figure), the value of sin⁡⁡α\sin ⁡\alpha will be:
    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field/With diagram
  167. 167A positive charge ' q\mathrm{q} ' of mass ' m\mathrm{m} ' is moving along the +x+x axis. We wish to apply a uniform magnetic field B for time Δt\Delta t so that the charge reverses its direction crossing the y\mathrm{y} axis at a distance d\mathrm{d}. Then:JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  168. 168A particle of charge 16×10−16C16 \times 10^{-16} \mathrm{C} moving with velocity 10 ms−110 \mathrm{~ms}^{-1} along xx-axis enters a region where magnetic field of induction
    B⃗\vec{B} is along the yy-axis and an electric field of magnitude 104Vm−110^4 \mathrm{Vm}^{-1} is along the negative zz-axis.
    If the charged particle continues moving along     xx-axis, the magnitude of B⃗\vec{B} is :    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  169. 169A uniform electric field E⃗\vec{E} exists between the plates of a charged condenser. A charged particle enters the space between the plates and perpendicular to E⃗\vec{E}. The path of the particle between the plates is a:JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  170. 170This question has Statement 1 and Statement 2. Of the four choices given after the Statements, choose the one that best describes the two Statements.
    Statement 1: A charged particle is moving at right angle to a static magnetic field. During the motion the kinetic energy of the charge remains unchanged.
    Statement 2: Static magnetic field exert force on a moving charge in the direction perpendicular to the magnetic field.    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  171. 171A proton and a deuteron are both accelerated through the same potential difference and enter in a magnetic field perpendicular to the direction of the field. If the deuteron follows a path of radius RR, assuming the neutron and proton masses are nearly equal, the radius of the proton's path will beJEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  172. 172The velocity of certain ions that pass undeflected through crossed electric field E=7.7kV/mE=7.7 \mathrm{k} \mathrm{V} / \mathrm{m} and magnetic field B=0.14 TB=0.14 \mathrm{~T} isJEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  173. 173Proton, Deuteron and alpha particle of the same kinetic energy are moving in circular trajectories in a constant magnetic field. The radii of proton, deuteron and alpha particle are respectively rp,rdr_p, r_d and rαr_\alpha. Which one of the following relations is correct?JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  174. 174A charged particle moves through a magnetic field perpendicular to its direction. ThenJEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  175. 175A charged particle with charge q\mathrm{q} enters a region of constant, uniform and mutually orthogonal fields E⃗\mathrm{\vec{E}} and B⃗\mathrm{\vec{B}} with a velocity v⃗\mathrm{\vec{v}} perpendicular to both E⃗\mathrm{\vec{E}} and B⃗\mathrm{\vec{B}}, and comes out without any change in magnitude or direction of v⃗\mathrm{\vec{v}}. ThenJEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  176. 176In a region, steady and uniform electric and magnetic fields are present. These two fields are parallel to each other. A charged particle is released from rest in this region. The path of the particle will be aJEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  177. 177A charged particle of mass m\mathrm{m} and charge qq travels on a circular path of radius rr that is perpendicular to a magnetic field B\mathrm{B}. The time taken by the particle to complete one revolution isJEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  178. 178A uniform electric field and a uniform magnetic field are acting along the same direction in a certain region. If an electron is projected along the direction of the fields with a certain velocity thenJEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  179. 179A particle of charge −16×10−18-16 \times 10^{-18} coulomb moving with velocity 10 ms−110 \mathrm{~ms}^{-1} along the x\mathrm{x}-axis enters a region where a magnetic field of induction B\mathrm{B} is along the y\mathrm{y}-axis, and an electric field of magnitude 104 V/m10^4 \mathrm{~V} / \mathrm{m} is along the negative z-axis. If the charged particle continues moving along the x\mathrm{x}-axis, the magnitude of B\mathrm{B} isJEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  180. 180A particle of mass MM and charge Q moving with velocity v→\overrightarrow{\mathrm{v}} describe a circular path of radius R\mathrm{R} when subjected to a uniform transverse magnetic field of induction B\mathrm{B}. The work done by the field when the particle completes one full circle isJEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  181. 181The time period of a charged particle undergoing a circular motion in a uniform magnetic field is
    independent of its    JEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  182. 182If an electron and a proton having same momenta enter perpendicular to a magnetic field, thenJEE Main/MCQ/Medium/Motion of Charged Particle in Magnetic Field
  183. 183A current carrying circular loop of radius 22 cm with unit normal n^=k^+i^2\hat{n} = \dfrac{\hat{k}+\hat{i}}{\sqrt{2}} is placed in a magnetic field, B⃗=B0(3i^+2k^)\vec{B} = B_0(3\hat{i}+2\hat{k}). If B0=4×10−3B_0 = 4\times 10^{-3} T and current I=1002I=100\sqrt{2} A, the torque experienced by the loop is ________ Wb·A. (π=3.14\pi=3.14)JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  184. 184A circular coil of radius 22 cm and 125125 turns carries a current of 11 A. The coil is placed in a uniform magnetic field of magnitude 0.40.4 T. The axis of the coil makes an angle of 30°30° with the direction of the magnetic field. The torque acting on the coil is α×10−4\alpha \times 10^{-4} N.m. The value of α\alpha is ______.
    (    π=3.14\pi=3.14)    JEE Main/Numerical/Medium/Force and Torque on Current Carrying Conductor
  185. 185Three long straight wires carrying current are arranged mutually parallel as shown in the figure. The force experienced by 15 cm length of wire QQ is ____\_\_\_\_.

    (    μo=4π×10−7 T.m/A\mu_{\mathrm{o}}=4 \pi \times 10^{-7} \mathrm{~T}. \mathrm{m} / \mathrm{A})    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor/With diagram
  186. 186A 4.0 cm long straight wire carrying a current of 8A is placed perpendicular to an uniform magnetic field of strength 0.15 T. The magnetic force on the wire is ______ mN.JEE Main/Numerical/Medium/Force and Torque on Current Carrying Conductor
  187. 187In a moving coil galvanometer, two moving coils M1M_1 and M2M_2 have the following particulars :
    $\begin{aligned}
    & \mathrm{R}_1=5 \Omega, \mathrm{~N}_1=15, \mathrm{~A}_1=3.6 \times 10^{-3} \mathrm{~m}^2, \mathrm{~B}_1=0.25 \mathrm{~T} \\
    & \mathrm{R}_2=7 \Omega, \mathrm{~N}_2=21, \mathrm{~A}_2=1.8 \times 10^{-3} \mathrm{~m}^2, \mathrm{~B}_2=0.50 \mathrm{~T}
    \end{aligned}$
    Assuming that torsional constant of the springs are same for both coils, what will be the ratio of voltage sensitivity of     M1M_1 and M2M_2 ?    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  188. 188A tightly wound long solenoid carries a current of 1.5 A . An electron is executing uniform circular motion inside the solenoid with a time period of 75 ns . The number of turns per metre in the solenoid is ……\ldots\ldots -.
    [Take mass of electron     me=9×10−31 kg\mathrm{m}_{\mathrm{e}}=9 \times 10^{-31} \mathrm{~kg}, charge of electron ∣qe∣=1.6×10−19C\left|\mathrm{q}_{\mathrm{e}}\right|=1.6 \times 10^{-19} \mathrm{C},
    μ0=4π×10−7 N A2,1 ns=10−9 s]\left.\mu_0=4 \pi \times 10^{-7} \frac{\mathrm{~N}}{\mathrm{~A}^2}, 1 \mathrm{~ns}=10^{-9} \mathrm{~s}\right]    JEE Main/Numerical/Medium/Force and Torque on Current Carrying Conductor
  189. 189Consider a moving coil galvanomenter (MCG):
    A. The torsional constant in moving coil galvanometer has dimentions     [ML2 T−2]\left[\mathrm{ML}^2 \mathrm{~T}^{-2}\right]
    B. Increasing the current sensitivity may not necessarily increase the voltage sensitivity.
    C. If we increase number of turns     (N)(\mathrm{N}) to its double (2 N)(2 \mathrm{~N}), then the voltage sensitivity doubles.
    D. MCG can be converted into an ammeter by introducing a shunt resistance of large value in parallel with galvanometer.
    E. Current sensitivity of MCG depends inversely on number of turns of coil.

    Choose the correct answer from the options given below:    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  190. 190Two long parallel wires XX and YY, separated by a distance of 6 cm , carry currents of 5A and 4A, respectively, in opposite directions as shown in the figure. Magnitude of the resultant magnetic field at point P at a distance of 4 cm from wire Y is x×10−5 Tx \times 10^{-5} \mathrm{~T}. The value of xx is__________ . Take permeability of free space as μ0=4π×10−7SI\mu_0=4 \pi \times 10^{-7} \mathrm{SI} units.

    JEE Main/Numerical/Medium/Force and Torque on Current Carrying Conductor/With diagram
  191. 191A square loop of edge length 2 m2 \mathrm{~m} carrying current of 2 A2 \mathrm{~A} is placed with its edges parallel to the xx yy axis. A magnetic field is passing through the x−yx-y plane and expressed as B⃗=B0(1+4x)k^\vec{B}=B_0(1+4 x) \hat{k}, where B0=5 TB_0=5 \mathrm{~T}. The net magnetic force experienced by the loop is _______ N\mathrm{N}.JEE Main/Numerical/Medium/Force and Torque on Current Carrying Conductor
  192. 192A 2 A current carrying straight metal wire of resistance 1Ω1 \Omega, resistivity 2×10−6Ωm2 \times 10^{-6} \Omega \mathrm{m}, area of cross-section 10 mm210 \mathrm{~mm}^2 and mass 500 g500 \mathrm{~g} is suspended horizontally in mid air by applying a uniform magnetic field B⃗\vec{B}. The magnitude of BB is _____×10−1 T\times 10^{-1} \mathrm{~T} (given, g=10 m/s2\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^2 ).JEE Main/Numerical/Medium/Force and Torque on Current Carrying Conductor
  193. 193The magnetic field existing in a region is given by B⃗=0.2(1+2x)k^ T\vec{B}=0.2(1+2 x) \hat{k} \mathrm{~T}. A square loop of edge 50 cm50 \mathrm{~cm} carrying 0.5 A current is placed in x−yx-y plane with its edges parallel to the x−yx-y axes, as shown in figure. The magnitude of the net magnetic force experienced by the loop is_____ mN\mathrm{mN}.
    JEE Main/Numerical/Medium/Force and Torque on Current Carrying Conductor/With diagram
  194. 194A moving coil galvanometer has 100100 turns and each turn has an area of 2.0cm2.2.0{cm}^{2}. The magnetic field produced by the magnet is 0.01T0.01T and the deflection in the coil is 0.050.05 radian when a current of 10mA10mA is passed through it. The torsional constant of the suspension wire is x×10−5N−m/rad.x\times {10}^{-5}N-m/rad. The value of xx is ______ .JEE Main/Numerical/Medium/Force and Torque on Current Carrying Conductor
  195. 195A uniform magnetic field of 2×10−3T2\times {10}^{-3}T acts along positive Y-direction. A rectangular loop of sides 20cm20cm and 10cm10cm with current of 5A5A is in Y-Z plane. The current is in anticlockwise sense with reference to negative X axis. Magnitude and direction of the torque is :JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  196. 196A rigid wire consists of a semicircular portion of radius RR and two straight sections. The wire is partially immerged in a perpendicular magnetic field B=B0j^B={B}_{0}\hat{j} as shown in figure. The magnetic force on the wire if it has a current ii is :JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor/With diagram
  197. 197The horizontal component of earth's magnetic field at a place is 3.5×10−5T3.5\times {10}^{-5}T. A very long straight conductor carrying current of 2A\sqrt{2}A in the direction from South east to North West is placed. The force per unit length experienced by the conductor is ________×10−6Nm−1\times {10}^{-6}N{m}^{-1}.JEE Main/Numerical/Medium/Force and Torque on Current Carrying Conductor
  198. 198A straight wire AB of mass 40g40g and length 50cm50cm is suspended by a pair of flexible leads in uniform magnetic field of magnitude 0.40T0.40T as shown in the figure. The magnitude of the current required in the wire to remove the tension in the supporting leads is _____ AA. (Take g=10ms−2)\left.g=10m{s}^{-2}\right).JEE Main/Numerical/Medium/Force and Torque on Current Carrying Conductor/With diagram
  199. 199Given below are two statements:
    Statement I: If the number of turns in the coil of a moving coil galvanometer is doubled then the current sensitivity becomes double.
    Statement II: Increasing current sensitivity of a moving coil galvanometer by only increasing the number of turns in the coil will also increase its voltage sensitivity in the same ratio
    In the light of the above statements, choose the correct answer from the options given below:    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  200. 200A current carrying rectangular loop PQRSPQRS is made of uniform wire. The length PR=QS=5cmandPQ=RS=100cmPR=QS=5cm\text{and}PQ=RS=100cm. If ammeter current reading changes from II to 2I2I, the ratio of magnetic forces per unit length on the wire PQPQ due to wire RSRS in the two cases respectively (fPQI:fPQ2I)\left({f}_{PQ}^{I}:{f}_{PQ}^{2I}\right) is:
    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor/With diagram
  201. 201A massless square loop, of wire of resistance 10Ω10\Omega, supporting a mass of 1g1g, hangs vertically with one of its sides in a uniform magnetic field of 103G{10}^{3}G, directed outwards in the shaded region. A dc voltage VV is applied to the loop. For what value of VV, the magnetic force will exactly balance the weight of the supporting mass of 1g1g?
    (If sides of the loop     =10cm,g=10ms−2=10cm,g=10m{s}^{-2})
    .    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor/With diagram
  202. 202A square loop of area 25cm225{cm}^{2} has a resistance of 10Ω10\Omega. The loop is placed in uniform magnetic field of magnitude 40.0T40.0T. The plane of loop is perpendicular to the magnetic field. The work done in pulling the loop out of the magnetic field slowly and uniformly in 1.01.0 sec, will beJEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  203. 203For a moving coil galvanometer, the deflection in the coil is 0.05rad0.05rad when a current of 10mA10mA is passed through it. If the torsional constant of suspension wire is 4.0×10–5Nmrad−14.0\times {10}^{–5}Nm{rad}^{-1}, the magnetic field is 0.01T0.01T and the number of turns in the coil is 200200, the area of each turn (in cm2{cm}^{2} ) is :JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  204. 204A single turn current loop in the shape of a right angle triangle with sides 5cm,12cm,13cm5cm,12cm,13cm is carrying a current of 2A2A. The loop is in a uniform magnetic field of magnitude 0.75T0.75T whose direction is parallel to the current in the 13cm13cm side of the loop. The magnitude of the magnetic force on the 5cm5cm side will be x130N\dfrac{x}{130}N. The value of xx is _______.JEE Main/Numerical/Medium/Force and Torque on Current Carrying Conductor
  205. 205Two long straight wires PP and QQ carrying equal current 10A10A each were kept parallel to each other at 5cm5cm distance. Magnitude of magnetic force experienced by 10cm10cm length of wire PP is F1{F}_{1}. If distance between wires is halved and currents on them are doubled, force F2{F}_{2} on 10cm10cm length of wire PP will be:JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  206. 206A wire XX of length 50cm50cm carrying a current of 2A2A is placed parallel to a long wire YY of length 5m5m. The wire YY carries a current of 3A3A. The distance between two wires is 5cm5cm and currents flow in the same direction. The force acting on the wire YY is :
    ​​​​​​​    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor/With diagram
  207. 207A triangular shaped wire carrying 10A10A current is placed in a uniform magnetic field of 0.5T0.5T, as shown in figure. The magnetic force on segment CDCD is (Given BC=CD=BD=5cmBC=CD=BD=5cm).
    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor/With diagram
  208. 208As shown in the figure, a metallic rod of linear density 0.45kgm−10.45kg{m}^{-1} is lying horizontally on a smooth incline plane which makes an angle of 45∘45^{\circ} with the horizontal. The minimum current flowing in the rod required to keep it stationary, when 0.15T0.15T magnetic field is acting on it in the vertical upward direction, will be
    (Use     g=10ms−2g=10m{s}^{-2})
    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor/With diagram
  209. 209The current sensitivity of a galvanometer can be increased by :
    (A) decreasing the number of turns
    (B) increasing the magnetic field
    (C) decreasing the area of the coil
    (D) decreasing the torsional constant of the spring
    Choose the most appropriate answer from the options given below :    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  210. 210Two parallel, long wires are kept 0.20m0.20m apart in vacuum, each carrying current of xAxA in the same direction. If the force of attraction per meter of each wire is 2×10−6N2\times {10}^{-6}N, then the value of xx is approximatelyJEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  211. 211Two long parallel conductors S1{S}_{1} and S2{S}_{2} are separated by a distance 10cm10cm and carrying currents of 4A4A and 2A2A respectively. The conductors are placed along xx-axis in X−YX-Y plane. There is a point PP located between the conductors (as shown in figure).
    A charge particle of     3π3\pi coulomb is passing through the point PP with velocity v⃗=(2i^+3j^)ms−1\vec{v}=\left(2\hat{i}+3\hat{j}\right)m{s}^{-1}; where i^\hat{i} & j^\hat{j} represents unit vector along xx & yyaxis respectively.
    The force acting on the charge particle is     4π×10−5(−xi^+2j^)N4\pi \times {10}^{-5}\left(-x\hat{i}+2\hat{j}\right)N. The value of xx is
    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor/With diagram
  212. 212Two 10cm10cm long, straight wires, each carrying a current of 5A5A are kept parallel to each other. If each wire experienced a force of 10−5N{10}^{-5}N, then separation between the wires is _____ cm.cm.JEE Main/Numerical/Medium/Force and Torque on Current Carrying Conductor
  213. 213A coil in the shape of an equilateral triangle of side 10cm10cm lies in a vertical plane between the pole pieces of permanent magnet producing a horizontal magnetic field 20mT20mT. The torque acting on the coil when a current of 0.2A0.2A is passed through it and its plane becomes parallel to the magnetic field will be x×10−5Nm\sqrt{x}\times {10}^{-5}Nm. The value of xx isJEE Main/Numerical/Medium/Force and Torque on Current Carrying Conductor
  214. 214A charge QQ is moving dl⃗d\vec{l} distance in the magnetic field B⃗\vec{B}. Find the value of work done by B⃗\vec{B}.JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  215. 215A proton, a deuteron and an α\alpha particle are moving with same momentum in a uniform magnetic field. The ratio of magnetic forces acting on them ______ is and their speed is ______ in the ratio.JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  216. 216A square loop of side 2a2a and carrying current II is kept in xzxz plane with its centre at origin. A long wire carrying the same current II is placed parallel to zz-axis and passing through point (0,b,0),(b>>a)\left(0,b,0\right),\left(b\gt \gt a\right). The magnitude of torque on the loop about zz-axis will be :JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  217. 217A square loop of side 2a,2a, and carrying current II is kept in XZXZ plane with its centre at origin. A long wire carrying the same current II is placed parallel to the zz-axis and passing through the point (0,b,0),(b>>a)(0,b,0),(b\gt \gt a). The magnitude of the torque on the loop about zz-axis is given by.JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  218. 218A small bar magnet is moved through a coil at constant speed from one end to the other. Which of the following series of observations will be seen on the galvanometer G\text{G} attached across the coil?
     Three positions shown describe: (a) the magnet's entry (b) magnet is completely inside and (c) magnet's exit.    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor/With diagram
  219. 219A charged particle carrying charge 1μC1\mu C is moving with velocity (2i^+3j^+4k^)ms−1(2\hat{i}+3\hat{j}+4\hat{k})m{s}^{-1}. If an external magnetic field of (5i^+3j^−6k^)×10−3T(5\hat{i}+3\hat{j}-6\hat{k})\times {10}^{-3}T exists in the region where the particle is moving then the force on the particle is F⃗×10−9N\vec{F}\times {10}^{-9}N . the vector F⃗\vec{F} is :JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  220. 220Proton with kinetic energy of 1MeV1MeV moves from south to north. It gets an acceleration of 1012m/s2{10}^{12}m/{s}^{2} by an applied magnetic field (west to east). The value of magnetic field: (Rest mass of proton is 1.6×10−27kg1.6\times {10}^{-27}kg )JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  221. 221The electric field of a plane electromagnetic wave is given by E⃗=E0i^+j^2cos⁡⁡(kz+ωt)\vec{E}={E}_{0}\dfrac{\hat{i}+\hat{j}}{\sqrt{2}}\cos ⁡\left(kz+\omega t\right) . At t=0t=0 , a positively charged particle is at the point (x,y,z)=(0,0,πk)\left(x,y,z\right)=\left(0,0,\dfrac{\pi }{k}\right) . If its instantaneous velocity at (t=0)\left(t=0\right) is v0k^{v}_{0}\hat{k} , the force acting on it due to the wave is:JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  222. 222Two wires AA & BB are carrying currents I1{I}_{1} and I2{I}_{2} as shown in the figure. The separation between them is dd . A third wire CC carrying a current II is to be kept parallel to them at a distance xx from AA such that the net force acting on it is zero. The possible values of xx are:
    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor/With diagram
  223. 223A moving coil galvanometer has a coil with 175175 turns and area 1cm2.1c{m}^{2}. It uses a torsion band of torsion constant 10−6Nm/rad{10}^{-6}Nm/rad The coil is placed in a magnetic field B parallel to its plane. The coil deflects by 1o{1}^{o} for a current of 1mA1mA The value of B (in tesla) is approximately:JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  224. 224A rectangular coil (Dimension 5cm×2.5cm5cm\times 2.5cm ) with 100100 turns, carrying a current of 3A3A in the clock-wise direction, is kept centered at the origin and in the X−ZX-Z plane. A magnetic field of 1T1T is applied along X−axisX-axis . If the coil is tilted through 45∘45^{\circ} about Z−axisZ-axis , then the torque on the coil is:JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  225. 225A rigid square loop of side ‘a’‘a’ and carrying current I2{I}_{2} is lying on a horizontal surface near a long current I1{I}_{1} carrying wire in the same plane as shown in figure. The net force on the loop due to the wire will be:
    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor/With diagram
  226. 226A circular coil having NN turns and radius rr carries a current I.I. It is held in the XZXZ plane in a magnetic field Bi^B\hat{i} . The torque on the coil due to the magnetic field is:JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  227. 227An infinitely long current carrying wire and a small current carrying loop are in the plane of the paper as shown. The radius of the loop is aa and distance of its centre from the wire is d(d≫a).d\left(d≫a\right). If the loop applies a force FF on the wire then:

    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor/With diagram
  228. 228In a certain region static electric and magnetic fields exist. The magnetic field is given by B⃗=B0(i^+2j^−4k^)\vec{B}={B}_{0}\left(\hat{i}+2\hat{j}-4\hat{k}\right). If a test charge moving with a velocity v⃗=v0(3i^−j^+2k^)\vec{v}={v}_{0}\left(3\hat{i}-\hat{j}+2\hat{k}\right) experiences no force in that region, then the electric field in the region, in SI units, is:JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  229. 229Consider a thin metallic sheet perpendicular to the plane of the paper moving with speed vv in a uniform magnetic field BB going into the plane of the paper (see figure). If charge densities σ1{\sigma }_{1} and σ2{\sigma }_{2} are induced on the left and right surfaces respectively of the sheet, then (ignore fringe effects)

    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor/With diagram
  230. 230Two long straight parallel wires, carrying (adjustable) currents I1{I}_{1} and I2{I}_{2} , are kept at a distance dd apart. If the force FF between the two wires is taken as 'positive' when the wires repel each other and 'negative' when the wires attract each other, the graph showing the dependence of FF, on the product I1I2{I}_{1}{I}_{2} , would be:JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  231. 231Two coaxial solenoids of different radii carry current II in the same direction. Let F1⃗\vec{{F}_{1}} be the magnetic force on the inner solenoid due to the outer one and F2⃗\vec{{F}_{2}} be the magnetic force on the outer solenoid due to the inner one. Then:JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  232. 232A rectangular loop of sides 10cm10cm and 5cm5cm, carrying a current II of 12A12A, is placed in different orientations as shown in the figure below.
    (a)     (b)

    (c)     (d)
    If there is a uniform magnetic field of     0.3T0.3T in the positive zz direction, in which orientations the loop would be in (i)(i) stable equilibrium and (ii)(ii) unstable equilibrium?    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor/With diagram
  233. 233A conductor lies along the z-axis at −1.5≤z<1.5m-\text{1.5}\leq \text{z}\lt \text{1.5}m and carries a fixed current of 10.0 A in −a^z{-\hat{\text{a}}}_{\text{z}} direction (see figure). For a field B⃗=3.0×10−4e−0.2xa^y\vec{\text{B}}=\text{3.0}\times 1{0}^{-4}{\text{e}}^{-\text{0.2x}}{\hat{\text{a}}}_{\text{y}} T, find the power required to move the conductor at constant speed to x = 2.0 m, y = 0 m in 5×10−3s5\times 1{0}^{-3}\text{s}. Assume parallel motion along the x-axis.

    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor/With diagram
  234. 234One of the two small circular coils, (none of them having any self - inductance) is suspended with a V-shaped copper wire, with plane horizontal. The other coil is placed just below the first one with plane horizontal. Both the coils are connected in series with a dc supply. The coils are found to attract each other with a force.
    Which one of the following statements is incorrect?    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  235. 235A rectangular loop of wire, supporting a mass mm, hangs with one end in a uniform magnetic field B⃗\vec{B} pointing out of the plane of the paper. A clockwise current is set up such that i>mg/Bai\gt m g / B a, where aa is the width of the loop. Then :
    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor/With diagram
  236. 236The circuit in figure consists of wires at the top and bottom and identical springs as the left and right sides. The wire at the bottom has a mass of 10 g10 \mathrm{~g} and is 5 cm5 \mathrm{~cm} long. The wire is hanging as shown in the figure. The springs stretch 0.5 cm0.5 \mathrm{~cm} under the weight of the wire and the circuit has a total resistance of 12Ω12 \Omega. When the lower wire is subjected to a static magnetic field, the springs, stretch an additional 0.3 cm0.3 \mathrm{~cm}. The magnetic field is
    JEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor/With diagram
  237. 237The magnetic force acting on charged particle of charge 2μC2 \mu \mathrm{C} in magnetic field of 2T2 T acting in y−y- direction, when the particle velocity is (2i^+3j^)×106 ms−1(2 \hat{i}+3 \hat{j}) \times 10^6 \mathrm{~ms}^{-1} isJEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  238. 238Due to the presence of the current l1\mathrm{l}_1 at the originJEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  239. 239Two thin, long parallel wires separated by a distance 'd' carry a current of 'i' AA in the same direction. They willJEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  240. 240Two long conductors, separated by a distance d\mathrm{d} carry current I1\mathrm{I}_1 and I2\mathrm{I}_2 in the same direction. They exert a force FF on each other. Now the current in one of them increased to two times and its direction reversed. The distance is also increased to 3 d3 \mathrm{~d}. The new value of the force between them isJEE Main/MCQ/Medium/Force and Torque on Current Carrying Conductor
  241. 241An insulated wire is wound so that it forms a flat coil with N=200N = 200 turns. The radius of the innermost turn is r1=3r_1 = 3 cm, and of the outermost turn r2=6r_2 = 6 cm. If 2020 mA current flows in it then the magnetic moment will be α×10−2\alpha \times 10^{-2} A.m2^2. The value of α\alpha is _____.JEE Main/MCQ/Medium/Magnetic Moment
  242. 242A straight magnetic strip has a magnetic moment of 44Am244 \mathrm{Am}^2. If the strip is bent in a semicircular shape, its magnetic moment will be _______ Am2\mathrm{Am}^2.
    (given     π=227\pi=\frac{22}{7} )    JEE Main/Numerical/Medium/Magnetic Moment
  243. 243A coil having 100 turns, area of 5×10−3 m25 \times 10^{-3} \mathrm{~m}^2, carrying current of 1 mA1 \mathrm{~mA} is placed in uniform magnetic field of 0.20 T0.20 \mathrm{~T} such a way that plane of coil is perpendicular to the magnetic field. The work done in turning the coil through 90∘90^{\circ} is _______ μJ\mu \mathrm{J}.JEE Main/Numerical/Medium/Magnetic Moment
  244. 244A circular coil having 200 turns, 2.5×10−4 m22.5 \times 10^{-4} \mathrm{~m}^2 area and carrying 100μA100 \mu \mathrm{A} current is placed in a uniform magnetic field of 1T. Initially the magnetic dipole moment (M⃗)(\vec{M}) was directed along B⃗\vec{B}. Amount of work, required to rotate the coil through 90∘90^{\circ} from its initial orientation such that M⃗\vec{M} becomes perpendicular to B⃗\vec{B}, is ______ μJ\mu \mathrm{J}.JEE Main/Numerical/Medium/Magnetic Moment
  245. 245A bar magnet with a magnetic moment 5.0Am25.0A{m}^{2} is placed in parallel position relative to a magnetic field of 0.4T0.4T. The amount of required work done in turning the magnet form parallel to antiparallel position relative to the field direction is ________.JEE Main/MCQ/Medium/Magnetic Moment
  246. 246The magnetic moments associated with two closely wound circular coils AA and BB of radius rA=10cmandrB=20cm{r}_{A}=10cm\text{and}{r}_{B}=20cm respectively are equal if: (Where NA,IAandNB,IB{N}_{A},{I}_{A}\text{and}{N}_{B},{I}_{B} are number of turn and current of AandBA\text{and}B respectively)JEE Main/MCQ/Medium/Magnetic Moment
  247. 247A wire of length 314cm314cm carrying current of 14A14A is bent to form a circle. The magnetic moment of the coil is A−m2A-{m}^{2}. [Given π=3.14\pi =3.14]JEE Main/Numerical/Medium/Magnetic Moment
  248. 248Two bar magnets oscillate in a horizontal plane in earth's magnetic field with time periods of 3s3s and 4s4srespectively. If their moments of inertia are in the ratio of 3:23:2 then the ratio of their magnetic moments will beJEE Main/MCQ/Medium/Magnetic Moment
  249. 249Two concentric circular loops of radii r1=30cm{r}_{1}=30cm and r2=50cm{r}_{2}=50cm are placed in X−YX-Y plane as shown in the figure. A current I=7AI=7A is flowing through them in the direction as shown in figure. The net magnetic moment of this system of two circular loops is approximately
    JEE Main/MCQ/Medium/Magnetic Moment/With diagram
  250. 250The magnetic moment of an electron (e)\left(e\right) revolving in an orbit around nucleus with an orbital angular momentum is given byJEE Main/MCQ/Medium/Magnetic Moment
  251. 251A bar magnet having a magnetic moment of 2.0×105JT−12.0\times {10}^{5}J{T}^{-1}, is placed along the direction of uniform magnetic field of magnitude B=14×10−5TB=14\times {10}^{-5}T. The work done in rotating the magnet slowly through 60∘60^{\circ} from the direction of field isJEE Main/MCQ/Medium/Magnetic Moment
  252. 252A long solenoid with 1000turnsm−11000turns{m}^{-1} has a core material with relative permeability 500500 and volume 103cm3.{10}^{3}{cm}^{3}. If the core material is replaced by another material having relative permeability of 750750 with same volume maintaining same current of 0.75A0.75A in the solenoid, the fractional change in the magnetic moment of the core would be approximately (x499).\left(\dfrac{x}{499}\right). Find the value of x.x.JEE Main/Numerical/Medium/Magnetic Moment
  253. 253A uniform conducting wire of length is 24a,24a, and resistance RR is wound up as a current carrying coil in the shape of an equilateral triangle of side aa and then in the form of a square of side aa. The coil is connected to a voltage source V0.{V}_{0}. The ratio of magnetic moment of the coils in case of equilateral triangle to that for square is 1:y1:\sqrt{y} where yy is ____________.JEE Main/Numerical/Medium/Magnetic Moment
  254. 254A charged particle going around in a circle can be considered to be a current loop. A particle of a mass mm carrying charge qq is moving in a plane with speed vv under the influence of magnetic field B⃗\vec{B}. The magnetic moment of this moving particle is :JEE Main/MCQ/Medium/Magnetic Moment
  255. 255An iron rod of volume 10−3m3{10}^{-3}{m}^{3} and relative permeability 10001000 is placed as core in a solenoid with10turnscm−110turns{cm}^{-1} . If a current of 0.5A0.5A is passed through the solenoid, then the magnetic moment of the rod will be :JEE Main/MCQ/Medium/Magnetic Moment
  256. 256A circular coil has moment of inertia 0.8kgm20.8kg{m}^{2} around any diameter and is carrying current to produce a magnetic moment of 20Am220{Am}^{2}. The coil is kept initially in a vertical position and it can rotate freely around a horizontal diameter. When a uniform magnetic field of 4T4T is applied along the vertical, it starts rotating around its horizontal diameter. The angular speed the coil acquires after rotating by 60o{60}^{o} will be :JEE Main/MCQ/Medium/Magnetic Moment
  257. 257A wire carrying current II is bent in the shapeABCDEFAABCDEFA as shown, where rectangle ABCDAABCDA and ADEFAADEFA are perpendicular to each other. If the sides of the rectangles are of lengths aa and bb, then the magnitude and direction of magnetic moment of the loop ABCDEFAABCDEFA is :
    JEE Main/MCQ/Medium/Magnetic Moment/With diagram
  258. 258A small circular loop of conducting wire has radius a and carries current I.I. It is placed in a uniform magnetic field BB perpendicular to its plane such that when rotated slightly about its diameter and released, it starts performing simple harmonic motion of time period T.T. The mass of the loop is mm then:JEE Main/MCQ/Medium/Magnetic Moment
  259. 259A square loop is carrying a steady current II and the magnitude of its magnetic dipole moment is mm . If this square loop is changed to a circular loop and it carries the same current, the magnitude of the magnetic dipole moment of circular loop will be:JEE Main/MCQ/Medium/Magnetic Moment
  260. 260An insulating thin rod of length ll has a linear charge density ρ(x)=ρ0xl\rho \left(x\right)={\rho }_{0}\dfrac{x}{l} on it. The rod is rotated about an axis passing through the origin (x=0)\left(x=0\right) and perpendicular to the rod. If the rod makes nn rotations per second, then the time averaged magnetic moment of the rod is:JEE Main/MCQ/Medium/Magnetic Moment
  261. 261A charge qq is spread uniformly over an insulated loop of radius rr. If it is rotated with an angular velocity ω\omega with respect to normal axis then magnetic moment of the loop is:JEE Main/MCQ/Medium/Magnetic Moment
  262. 262A short bar magnet placed with its axis at 30∘30^{\circ} with an external field of 800 Gauss, experiences a torque of 0.016 N.m0.016 \mathrm{~N}. \mathrm{m}. The work done in moving it from most stable to most unstable position is α×10−3 J\alpha \times 10^{-3} \mathrm{~J}. The value of α\alpha is ____\_\_\_\_.JEE Main/Numerical/Medium/Magnetic Dipole
  263. 263A magnetic dipole experiences a torque of 803 N m80 \sqrt{3} \mathrm{~N} \mathrm{~m} when placed in uniform magnetic field in such a way that dipole moment makes angle of 60∘60^{\circ} with magnetic field. The potential energy of the dipole is :JEE Main/MCQ/Medium/Magnetic Dipole
  264. 264The magnetic potential due to a magnetic dipole at a point on its axis situated at a distance of 20cm20cm from its center is 1.5×10−5Tm1.5\times {10}^{-5}Tm. The magnetic moment of the dipole is _______ Am2A{m}^{2}. (Given : μ04π=10−7TmA−1\dfrac{{\mu }_{0}}{4\pi }={10}^{-7}Tm{A}^{-1})JEE Main/Numerical/Medium/Magnetic Dipole
  265. 265Given below two statements : One is labelled as Assertion (A) and other is labelled as Reason (R).
    Assertion (A): Non-polar materials do not have any permanent dipole moment.
    Reason (R): When a non-polar material is placed in an electric field, the centre of the positive charge distribution of it's individual atom or molecule coincides with the centre of the negative charge distribution.
    In the light of above statements, choose the most appropriate answer from the options given below.    JEE Main/MCQ/Medium/Magnetic Dipole
  266. 266Two short magnetic dipoles m1{m}_{1} and m2{m}_{2} each having magnetic moment of 1Am21A{m}^{2} are placed at point OO and PP respectively. The distance between OPOP is 1m1m. The torque experienced by the magnetic dipole m2{m}_{2} due to the presence of m1{m}_{1} is ________\times {10}^{-7}Nm
    JEE Main/Numerical/Medium/Magnetic Dipole/With diagram
  267. 267Two magnetic dipoles XX and YY are placed at a separation dd , with their axes perpendicular to each other. The dipole moment of YY is twice that of XX . A particle of charge qq is passing through their mid-point PP , at angle θ=45o\theta ={45}^{o} with the horizontal line, as shown in figure. What would be the magnitude of force on the particle at that instant? ( dd is much larger than the dimension of the dipole)
    JEE Main/MCQ/Medium/Magnetic Dipole/With diagram
  268. 268The dipole moment of a circular loop carrying a current I, is m and the magnetic field at the centre of the loop is B1{B}_{1} . When the dipole moment is doubled by keeping the current constant, the magnetic field at the centre of the loop is B2{B}_{2} . The ratio B1B2\dfrac{{B}_{1}}{{B}_{2}} is:JEE Main/MCQ/Medium/Magnetic Dipole
  269. 269A uniform magnetic field BB of 0.3T0.3T is along the positive Z\text{Z} -direction. A rectangular loop (abcdabcd) of sides 10cm×5cm10cm\times 5cm carries a current II of 12A12A. Out of the following different orientations which one corresponds to stable equilibrium?JEE Main/MCQ/Medium/Magnetic Dipole
  270. 270A magnetic dipole in a uniform magnetic field has: (Take zero potential energy when magnetic dipole is perpendicular to magnetic field)JEE Main/MCQ/Medium/Magnetic Dipole
  271. 271A magnetic dipole is acted upon by two magnetic fields which are inclined to each other at an angle of 75o{75}^{o}. One of the fields has a magnitude of 15mT15mT. The dipole attains stable equilibrium at an angle of 30o{30}^{o} with this field. The magnitude of the other field (in mTmT) is close toJEE Main/MCQ/Medium/Magnetic Dipole
  272. 272Two identical long current carrying wires are bent into the shapes shown in the following figures. If the magnitude of magnetic fields at the centres P and Q of a semicircular arc are B1B_1 and B2B_2 respectively, then the ratio B1B2\dfrac{B_1}{B_2} is _______.
    JEE Main/MCQ/Medium/Biot-Savart’s Law and Ampere’s Circuital Law/With diagram
  273. 273

    N equally spaced charges each of value q , are placed on a circle of radius R . The circle rotates about its axis with an angular velocity     ω\omega as shown in the figure. A bigger Amperian loop B encloses the whole circle where as a smaller Amperian loop A encloses a small segment. The difference between enclosed currents, IA−IBI_A-I_B, for the given Amperian loops is    JEE Main/MCQ/Medium/Biot-Savart’s Law and Ampere’s Circuital Law/With diagram
  274. 274Given below are two statements :
    Statement (I) : When currents vary with time, Newton's third law is valid only if momentum carried by the electromagnetic field is taken into account.
    Statement (II) : Ampere's circuital law does not depend on Biot-Savart's law.
    In the light of the above statements, choose the correct answer from the options given below :    JEE Main/MCQ/Medium/Biot-Savart’s Law and Ampere’s Circuital Law
  275. 275An element Δl=Δxi^\Delta l=\Delta x \hat{i} is placed at the origin and carries a large current I=10 AI=10 \mathrm{~A}. The magnetic field on the yy-axis at a distance of 0.5 m0.5 \mathrm{~m} from the elements Δx\Delta x of 1 cm1 \mathrm{~cm} length is:
    JEE Main/MCQ/Medium/Biot-Savart’s Law and Ampere’s Circuital Law/With diagram
  276. 276Two parallel long current carrying wire separated by a distance 2r2 r are shown in the figure. The ratio of magnetic field at AA to the magnetic field produced at CC is x7\frac{x}{7}. The value of xx is _____
    JEE Main/Numerical/Medium/Biot-Savart’s Law and Ampere’s Circuital Law/With diagram

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