Physics · JEE Main, NEET

Dual Nature of Matter

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

187MCQ13Numerical8With diagram
Start with question 1 Revise Modern Physics firstSee it move: Photoelectric effect and matter waves
  1. 1When radiation of wavelength λ\lambda falls on a metal, stopping potential is 3V03V_0. When wavelength is 2λ2\lambda, stopping potential is V0V_0. The threshold wavelength is:JEE Main/MCQ/Medium
  2. 2The slope of stopping potential versus frequency graph for photoelectric effect gives:NEET/MCQ/Medium
  3. 3In a photoelectric experiment, graph of stopping potential V0V_0 versus frequency ν\nu has slope equal to:JEE Main/MCQ/Medium
  4. 4An oil drop of the radius 2mm2mm with a density 3g3g cm−3{cm}^{-3} is held stationary under a constant electric field 3.55×105Vm−13.55\times {10}^{5}V{m}^{-1} in the Millikan's oil drop experiment. What is the number of excess electrons that the oil drop will possess? (considerg=9.81ms−2)\left(\text{consider}g=9.81m{s}^{-2}\right).JEE Main/MCQ/Medium/Cathode Rays and Positive Rays
  5. 5The de Broglie wavelength for an electron accelerated through the potential difference of V1V_1 volt is λ1\lambda_1. When the potential difference is changed to V2V_2 volt, the associated de Broglie wavelength is increased by 50%50\%. If (V1/V2)=(9/α)(V_1/V_2) = (9/\alpha), then the value of α\alpha is __________.JEE Main/Numerical/Medium/Matter Waves
  6. 6An electron is travelling with a velocity vv in free space and when it enters a medium, its velocity is reduced by 20%20\%. The de Broglie wavelength of electron in the medium is αλ0\alpha\lambda_0, where λ0\lambda_0 is its de Broglie wavelength in free space. The value of α\alpha is _______.JEE Main/MCQ/Medium/Matter Waves
  7. 7An electron of mass mm is moving in an electric field E⃗=−2E0i^\vec{E} = -2E_0\hat{i} (E0=E_0 = constant >0\gt 0), with an initial velocity V⃗=v0i^\vec{V} = v_0\hat{i} (v0=v_0 = constant >0\gt 0). If λ0=h4mv0\lambda_0 = \dfrac{h}{4mv_0}, its de Broglie wavelength at time tt is __________.
    (    e=e = charge of electron)    JEE Main/MCQ/Medium/Matter Waves
  8. 8The de Broglie wavelength associated with an electron accelerated through a potential difference V is λe\lambda_e and the de Broglie wavelength associated with a proton accelerated through the same potential difference is λp\lambda_p. If their corresponding masses are mem_e and mpm_p, respectively, then the ratio of their de Broglie wavelengths (λeλp)\left(\dfrac{\lambda_e}{\lambda_p}\right) is ______.JEE Main/MCQ/Medium/Matter Waves
  9. 9The ratio of de Broglie wavelength of a deutron with kinetic energy EE to that of an alpha particle with kinetic energy 2E2 E, is n:1n: 1. The value of nn is ____\_\_\_\_.
    (Assume mass of proton     == mass of neutron) :    JEE Main/Numerical/Medium/Matter Waves
  10. 10The de Broglie wavelength of an oxygen molecule at 27∘C27^{\circ} \mathrm{C} is x×10−12 mx \times 10^{-12} \mathrm{~m}. The value of xx is (take Planck's constant =6.63×10−34 J.s=6.63 \times 10^{-34} \mathrm{~J}. \mathrm{s}, Boltzmann constant =1.38×10−23 J/K=1.38 \times 10^{-23} \mathrm{~J} / \mathrm{K}, mass of oxygen molecule =5.31×10−26 kg=5.31 \times 10^{-26} \mathrm{~kg})JEE Main/MCQ/Medium/Matter Waves
  11. 11A particle having electric charge 3×10−19C3 \times 10^{-19} \mathrm{C} and mass 6×10−27 kg6 \times 10^{-27} \mathrm{~kg} is accelerated by applying an electric potential of 1.21 V. Wavelength of the matter wave associated with the particle is α×10−12 m\alpha \times 10^{-12} \mathrm{~m}. The value of α\alpha is ____\_\_\_\_ - (Take Planck's constant =6.6×10−34 J.s=6.6 \times 10^{-34} \mathrm{~J}. \mathrm{s})JEE Main/Numerical/Medium/Matter Waves
  12. 12A photo-emissive substance is illuminated with a radiation of wavelength λi\lambda_i so that it releases electrons with de-Broglie wavelength λe\lambda_e. The longest wavelength of radiation that can emit photoelectron is λ0\lambda_0. Expression for de-Broglie wavelength is given by :
    (     m:\mathrm{m}: mass of the electron, h:\mathrm{h}: Planck's constant and cc : speed of light)    JEE Main/MCQ/Medium/Matter Waves
  13. 13An electron with mass ' mm ' with an initial velocity (t=0)v→=v0i^(v0>0)(\mathrm{t}=0) \overrightarrow{\mathrm{v}}=\mathrm{v}_0 \hat{\mathrm{i}} \quad\left(\mathrm{v}_0 \gt 0\right) enters a magnetic field B⃗=B0j^\vec{B}=B_0 \hat{j}. If the initial de-Broglie wavelength at t=0\mathrm{t}=0 is λ0\lambda_0 then its value after time ' t ' would be :JEE Main/MCQ/Medium/Matter Waves
  14. 14If \(\lambda\) and \(K\) are de Broglie wavelength and kinetic energy, respectively, of a particle with constant mass. The correct graphical representation for the particle will beJEE Main/MCQ/Medium/Matter Waves
  15. 15A proton of mass ' mpm_{\mathrm{p}} ' has same energy as that of a photon of wavelength ' λ\lambda '. If the proton is moving at non-relativistic speed, then ratio of its de Broglie wavelength to the wavelength of photon is.JEE Main/MCQ/Medium/Matter Waves
  16. 16The energy EE and momentum pp of a moving body of mass mm are related by some equation. Given that c represents the speed of light, identify the correct equationJEE Main/MCQ/Medium/Matter Waves
  17. 17An electron of mass ' m ' with an initial velocity v→=v0i^(v0>0)\overrightarrow{\mathrm{v}}=\mathrm{v}_0 \hat{i}\left(\mathrm{v}_0\gt0\right) enters an electric field E→=−Eok^\overrightarrow{\mathrm{E}}=-\mathrm{E}_{\mathrm{o}} \hat{\mathrm{k}}. If the initial de Broglie wavelength is λ0\lambda_0, the value after time t would beJEE Main/MCQ/Medium/Matter Waves
  18. 18A sub-atomic particle of mass 10−30 kg10^{-30} \mathrm{~kg} is moving with a velocity 2.21×106 m/s2.21 \times 10^6 \mathrm{~m} / \mathrm{s}. Under the matter wave consideration, the particle will behave closely like \qquad (h=6.63×10−34 J.s)\left(\mathrm{h}=6.63 \times 10^{-34} \mathrm{~J} . \mathrm{s}\right)JEE Main/MCQ/Medium/Matter Waves
  19. 19An electron in the ground state of the hydrogen atom has the orbital radius of 5.3×10−11 m5.3 \times 10^{-11} \mathrm{~m} while that for the electron in third excited state is 8.48×10−10 m8.48 \times 10^{-10} \mathrm{~m}. The ratio of the de Broglie wavelengths of electron in the excited state to that in the ground state isJEE Main/MCQ/Medium/Matter Waves
  20. 20A proton, an electron and an alpha particle have the same energies. Their de-Broglie wavelengths will be compared as :JEE Main/MCQ/Medium/Matter Waves
  21. 21A proton and an electron have the same de Broglie wavelength. If Kp\mathrm{K}_{\mathrm{p}} and Ke\mathrm{K}_{\mathrm{e}} be the kinetic energies of proton and electron respectively, then choose the correct relation :JEE Main/MCQ/Medium/Matter Waves
  22. 22A proton and an electron are associated with same de-Broglie wavelength. The ratio of their kinetic energies is:
    (Assume h=6.63     ×10−34 J s, me=9.0×10−31 kg\times 10^{-34} \mathrm{~J} \mathrm{~s}, \mathrm{~m}_{\mathrm{e}}=9.0 \times 10^{-31} \mathrm{~kg} and mp=1836\mathrm{m}_{\mathrm{p}}=1836 times me\mathrm{m}_{\mathrm{e}} )    JEE Main/MCQ/Medium/Matter Waves
  23. 23The de Broglie wavelengths of a proton and an α\alpha particle are λ\lambda and 2λ2\lambda respectively. The ratio of the velocities of proton and α\alpha particle will be :JEE Main/MCQ/Medium/Matter Waves
  24. 24The de-Broglie wavelength of an electron is the same as that of a photon. If velocity of electron is 2525% of the velocity of light, then the ratio of K.E. of electron and K.E. of photon will be:JEE Main/MCQ/Medium/Matter Waves
  25. 25The de Broglie wavelength of an electron having kinetic energy EE is λ\lambda. If the kinetic energy of electron becomes E4\dfrac{E}{4}, then its de-Broglie wavelength will be:JEE Main/MCQ/Medium/Matter Waves
  26. 26A proton and an α\alpha-particle are accelerated from rest by 2V2V and 4V4V potentials, respectively. The ratio of their de-Broglie wavelength is :JEE Main/MCQ/Medium/Matter Waves
  27. 27The ratio of the de-Broglie wavelengths of proton and electron having same kinetic energy:
    (Assume     mp=me×1849{m}_{p}={m}_{e}\times 1849)    JEE Main/MCQ/Medium/Matter Waves
  28. 28The de Broglie wavelength of a molecule in a gas at room temperature (300K)\left(300K\right) is λ1{\lambda }_{1}. If the temperature of the gas is increased to 600K600K, then the de Broglie wavelength of the same gas molecule becomesJEE Main/MCQ/Medium/Matter Waves
  29. 29Proton (P)(P) and electron (e)(e) will have same de-Broglie wavelength when the ratio of their momentum is (assume, mp=1849{m}_{p}=1849 me{m}_{e})JEE Main/MCQ/Medium/Matter Waves
  30. 30The kinetic energy of an electron, α−\alpha -particle and a proton are given as 4K,2K4K,2K and KK respectively. The de-Broglie wavelength associated with electron (λe),α−({\lambda }_{e}),\alpha -particle (λα)({\lambda }_{\alpha }) and the proton (λp)({\lambda }_{p}) are as follows:JEE Main/MCQ/Medium/Matter Waves
  31. 31A proton moving with one tenth of velocity of light has a certain de Broglie wavelength of λ\lambda. An alpha particle having certain kinetic energy has the same de-Brogle wavelength λ\lambda. The ratio of kinetic energy of proton and that of alpha particle is :JEE Main/MCQ/Medium/Matter Waves
  32. 32An electron accelerated through a potential difference V1{V}_{1} has a de-Broglie wavelength of λ\lambda. When the potential is changed to V2{V}_{2}, its de-Broglie wavelength increases by 5050%. The value of (V1V2)\left(\dfrac{{V}_{1}}{{V}_{2}}\right) is equal to :JEE Main/MCQ/Medium/Matter Waves
  33. 33The ratio of de-Broglie wavelength of an α\alpha-particle and a proton accelerated from rest by the same potential is 1m\dfrac{1}{\sqrt{m}} , the value of mm is:JEE Main/MCQ/Medium/Matter Waves
  34. 34Electron beam used in an electron microscope, when accelerated by a voltage of 20kV20kV has a de-Broglie wavelength of λ0{\lambda }_{0}. If the voltage is increased to 40kV40kV then the de-Broglie wavelength associated with the electron beam would be:JEE Main/MCQ/Medium/Matter Waves
  35. 35An α\alpha particle, a proton and an electron have the same kinetic energy. Which one of the following is correct in case of their de-Broglie wavelength:JEE Main/MCQ/Medium/Matter Waves
  36. 36An α\alpha particle and a proton are accelerated from rest through the same potential difference. The ratio of linear momenta acquired by above two particals will be :JEE Main/MCQ/Medium/Matter Waves
  37. 37The kinetic energy of emitted electron is EE when the light incident on the metal has wavelength λ\lambda. To double the kinetic energy, the incident light must have wavelength:JEE Main/MCQ/Medium/Matter Waves
  38. 38The equation λ=1.227xnm\lambda =\dfrac{1.227}{x}nm can be used to find the de-Broglie wavelength of an electron. In this equation xx stands for :
    Where,
    m=m= mass of electron
    P=P= momentum of electron
    K=K= Kinetic energy of electron
    V=V= Accelerating potential in volts for electron    JEE Main/MCQ/Medium/Matter Waves
  39. 39An electron (mass mm) with an initial velocity v⃗=v0i^(v0>0)\vec{v}={v}_{0}\hat{i}\left({v}_{0}\gt 0\right) is moving in an electric field E⃗=−E0i^(E0>0)\vec{E}=-{E}_{0}\hat{i}\left({E}_{0}\gt 0\right) where E0{E}_{0} is constant. If at t=0t=0, de-Broglie wavelength is λ0=hmv0{\lambda }_{0}=\dfrac{h}{m{v}_{0}}, then its de-Broglie wavelength after time tt is given byJEE Main/MCQ/Medium/Matter Waves
  40. 40A nucleus of mass MM at rest splits into two parts having masses M′3\dfrac{{M}^{'}}{3} and 2M′3(M′<M)\dfrac{2{M}^{'}}{3}\left({M}^{'}\lt M\right). The ratio of de Broglie wavelength of two parts will beJEE Main/MCQ/Medium/Matter Waves
  41. 41The ratio of wavelengths of proton and deuteron accelerated by potential Vp{V}_{p} and Vd{V}_{d} is 1:21:\sqrt{2}. Then, the ratio of Vp{V}_{p} to Vd{V}_{d} will beJEE Main/MCQ/Medium/Matter Waves
  42. 42The de Broglie wavelengths for an electron and a photon are λe{\lambda }_{e} and λp{\lambda }_{p} respectively. For the same kinetic energy of electron and photon, which of the following presents the correct relation between the de Broglie wavelengths of two?JEE Main/MCQ/Medium/Matter Waves
  43. 43An α\alpha particle and a carbon 1212 atom has same kinetic energy KK. The ratio of their de-Broglie wavelengths (λα:λC12)\left({\lambda }_{\alpha }:{\lambda }_{C12}\right) isJEE Main/MCQ/Medium/Matter Waves
  44. 44An electron with speed vv and a photon with speed cc have the same de-Broglie wavelength. If the kinetic energy and momentum of electron are Ee{E}_{e} and Pe{P}_{e} and that of photon are Eph{E}_{ph} and Pph{P}_{ph} respectively. Which of the following is correct?JEE Main/MCQ/Medium/Matter Waves
  45. 45A proton, a neutron, an electron and an α\alpha-particle have same energy. If λp,λn,λe{\lambda }_{p},{\lambda }_{n},{\lambda }_{e} and λα{\lambda }_{\alpha } are the de Broglie's wavelengths of proton, neutron, electron and α\alpha particle respectively, then choose the correct relation from the followingJEE Main/MCQ/Medium/Matter Waves
  46. 46The temperature of an ideal gas in three dimensions is 300K.300K. The corresponding de-Broglie wavelength of the electron approximately at 300K300K is:
    [me=\left[{m}_{e}=\right.mass of electron =9×10−31kg=9\times {10}^{-31}kg, h=h=Planck constant =6.6×10−34Js=6.6\times {10}^{-34}Js, kB={k}_{B}=Boltzmann constant=1.38×10−23JK−1]\left.=1.38\times {10}^{-23}J{K}^{-1}\right]    JEE Main/MCQ/Medium/Matter Waves
  47. 47Consider two separate ideal gases of electrons and protons having same number of particles. The temperature of both the gases are same. The ratio of the uncertainty in determining the position of an electron to that of a proton is proportional to:JEE Main/MCQ/Medium/Matter Waves
  48. 48A moving proton and electron have the same de-Broglie wavelength. If KK and PP denote the K.E.K.E. and momentum respectively. Then choose the correct option :JEE Main/MCQ/Medium/Matter Waves
  49. 49The de-Broglie wavelength of a particle having kinetic energy EE is λ.\lambda . How much extra energy must be given to this particle so that the de-Broglie wavelength reduces to 7575% of the initial value?JEE Main/MCQ/Medium/Matter Waves
  50. 50A particle of mass 9.1×10−31kg9.1\times {10}^{-31}kg travels in a medium with a speed of 106ms−1{10}^{6}m{s}^{-1} and a photon of radiation of linear momentum 10−27kgms−1{10}^{-27}kgm{s}^{-1} travels in a vacuum. The wavelength of the photon is ____ times the wavelength of the particle.JEE Main/Numerical/Medium/Matter Waves
  51. 51An electron moving with speed vv and a photon moving with speed cc, have the same D-Broglie wavelength. The ratio of the kinetic energy of the electron to that of a photon is:JEE Main/MCQ/Medium/Matter Waves
  52. 52A particle of mass 4M4M at rest disintegrates into two particles of mass MM and 3M3M, respectively, having non zero velocities. The ratio of de-Broglie wavelength of particle of mass MM to that of mass 3M3M will be:JEE Main/MCQ/Medium/Matter Waves
  53. 53What should be the order of arrangement of de-Broglie wavelength of electron (λe)\left({\lambda }_{e}\right), an α\alpha-particle (λα)\left({\lambda }_{\alpha }\right) and proton (λp)\left({\lambda }_{p}\right) given that all have the same kinetic energy ?JEE Main/MCQ/Medium/Matter Waves
  54. 54An electron of mass me{m}_{e} and a proton of mass mP{m}_{P} are accelerated through the same potential difference. The ratio of the de-Broglie wavelength associated with the electron to that with the proton isJEE Main/MCQ/Medium/Matter Waves
  55. 55An electron having de-Broglie wavelength λ\lambda is incident on a target in a XX-ray tube. Cut-off wavelength of emitted XX-ray is:JEE Main/MCQ/Medium/Matter Waves
  56. 56A particle is travelling 44 times as fast as an electron. Assuming the ratio of de-Broglie wavelength of a particle to that of electron is 2:1,2:1, the mass of the particle is :-JEE Main/MCQ/Medium/Matter Waves
  57. 57An electron of mass mm and a photon have same energy E.E. The ratio of wavelength of electron to that of photon is : (cc being the velocity of light)JEE Main/MCQ/Medium/Matter Waves
  58. 58The de-Broglie wavelength associated with an electron and a proton were calculated by accelerating them through same potential of 100V100V. What should nearly be the ratio of their wavelengths ?? (mp=1.00727u,me=0.00055u)\left({m}_{p}=1.00727u,{m}_{e}=0.00055u\right)JEE Main/MCQ/Medium/Matter Waves
  59. 59An electron of mass me{m}_{e} and a proton of mass mp=1836me{m}_{p}=1836{m}_{e} are moving with the same speed. The ratio of their de Broglie wavelength λelectronλproton\dfrac{{\lambda }_{electron}}{{\lambda }_{proton}} will be :JEE Main/MCQ/Medium/Matter Waves
  60. 60An α\alpha particle and a proton are accelerated from rest by a potential difference of 200V200V. After this, their de Broglie wavelengths are λα{\lambda }_{\alpha } and λp{\lambda }_{p} respectively. The ratio λpλα\dfrac{{\lambda }_{p}}{{\lambda }_{\alpha }} is :JEE Main/MCQ/Medium/Matter Waves
  61. 61The de Broglie wavelength of a proton and α\alpha-particle are equal. The ratio of their velocities isJEE Main/MCQ/Medium/Matter Waves
  62. 62An electron, a doubly ionized helium ion (He++He^{++}) and proton are having the same kinetic energy. The relation between their respective de-Broglie wavelength λe∗λHe++{\lambda }_{{e}^{*}}{\lambda }_{{He}^{++}} and λp{\lambda }_{p} is :JEE Main/MCQ/Medium/Matter Waves
  63. 63Particle AA of mass mA=m2{\text{m}}_{\text{A}}=\dfrac{\text{m}}{2} moving along the x\text{x} -axis with velocity v0{\text{v}}_{0} collides elastically with another particle B\text{B} at rest having mass mB=m3{\text{m}}_{\text{B}}=\dfrac{\text{m}}{3}. If both the particles move along the x\text{x} -axis after the collision, the change ∆λ∆\lambda in the wavelength of the particle A\text{A}, in terms of its de-Broglie wavelength (λ0)\left({\lambda }_{0}\right) before the collision is:JEE Main/MCQ/Medium/Matter Waves
  64. 64A particle is moving 55 times as fast as an electron. The ratio of the de-Broglie wavelength of the particle to that of the electron is 1.878×10–41.878\times {10}^{–4}. The mass of the particle is close to :JEE Main/MCQ/Medium/Matter Waves
  65. 65An electron of mass mm and magnitude of charge ee at rest, gets accelerated by a constant electric field EE. The rate of change of de-Broglie wavelength of this electron at a time tt is (ignore relativistic effects)JEE Main/MCQ/Medium/Matter Waves
  66. 66A particle moving with kinetic energy EE has de Broglie wavelength λ\lambda . If energy ΔE\Delta E is added to its energy, the wavelength become λ2\dfrac{\lambda }{2} . Value of ΔE,\Delta E, is:JEE Main/MCQ/Medium/Matter Waves
  67. 67An electron (mass mm ) with initial velocity v⃗=v0i^+v0j^\vec{v}={v}_{0}\hat{i}+{v}_{0}\hat{j} is in an electric filed E⃗=−E0k^.\vec{E}=-{E}_{0}\hat{k}. If λ0{\lambda }_{0} is initial de-Broglie wavelength of electron, its de-Broglie wave length at time tt is given by:JEE Main/MCQ/Medium/Matter Waves
  68. 68When photon of energy 4.0eV4.0eV strikes the surface of a metal A,A, the ejected photoelectrons have maximum kinetic energy TAeV{T}_{A}eV and de-Broglie wavelength λA.{\lambda }_{A}. The maximum kinetic energy of photoelectrons liberated from another metal BB by photon of energy 4.50eV4.50eV is TB=(TA−1.5)eV.{T}_{B}=\left({T}_{A}-1.5\right)eV. If the de-Broglie wavelength of these photoelectrons λB=2λA,{\lambda }_{B}=2{\lambda }_{A}, then the work function of metal BB is:JEE Main/MCQ/Medium/Matter Waves
  69. 69An electron (of mass mm ) and a photon have the same energy EE in the range of a few eVeV. The ratio of the de-Broglie wavelength associated with the electron and the wavelength of the photon is ( c=c= speed of light in vacuum)JEE Main/MCQ/Medium/Matter Waves
  70. 70Consider an electron in a hydrogen atom, revolving in its second excited state (having radius 4.65A˚4.65\text{Å} ). The de-Broglie wavelength of this electron is:JEE Main/MCQ/Medium/Matter Waves
  71. 71A particle ′P′'P' is formed due to a completely inelastic collision of particles ′x′'x' and ′y′'y' having de-Broglie wavelengths ′λx′'{\lambda }_{x}' and ′λy′'{\lambda }_{y}' respectively. If xx and yy were moving in opposite directions, then the de-Broglie wavelength of ′P′'P' is:JEE Main/MCQ/Medium/Matter Waves
  72. 72A nucleus A,A, with a finite de-broglie wavelength λA,{\lambda }_{A}, undergoes spontaneous fission into two nuclei BB and CC of equal mass. BB flies in the same direction as that of A,A, while CC flies in the opposite direction with a velocity equal to half of that of B.B. The de-Broglie wavelengths λB{\lambda }_{B} and λC{\lambda }_{C} of B and C are respectively:JEE Main/MCQ/Medium/Matter Waves
  73. 73Two particles move at right angle to each other. Their de Broglie wavelengths are λ1{\lambda }_{1} and λ2{\lambda }_{2} respectively. The particles suffer perfectly inelastic collision. The de Broglie wavelength λ\lambda of the final particle, is given by:JEE Main/MCQ/Medium/Matter Waves
  74. 74A particle AA of mass mm and charge qq is accelerated by a potential difference of 50V.50V. Another particle BB of mass 4m4m and charge qq is accelerated by a potential difference of 2500V.2500V. The ratio of de-Broglie wavelengths λAλB\dfrac{{\lambda }_{A}}{{\lambda }_{B}} is close to:JEE Main/MCQ/Medium/Matter Waves
  75. 75If the deBroglie wavelength of an electron is equal to 10−10^{-} times the wavelength of a photon of frequency 6×10146 \times 10^{14} Hz\mathrm{Hz}, then the speed of electron is equal to :

    (Speed of light     =3×108 m/s)\left.=3 \times 10^{8} \mathrm{~m} / \mathrm{s}\right)

    Planck's constant     =6.63×10−34 J.s=6.63 \times 10^{-34} \mathrm{~J} . \mathrm{s}

    Mass of electron     =9.1×10−31 kg)\left.=9.1 \times 10^{-31} \mathrm{~kg}\right)    JEE Main/MCQ/Medium/Matter Waves
  76. 76In an electron microscope, the resolution that can be achieved is of the order of the wavelength of electrons used. To resolve a width of 7.5×10−12m,7.5\times {10}^{-12}m, the minimum electron energy required is close to:JEE Main/MCQ/Medium/Matter Waves
  77. 77The de-Broglie wavelength (λB)\left({\lambda }_{B}\right) associated with the electron orbiting in the second excited state of hydrogen atom is related to that in the ground state (λG)\left({\lambda }_{G}\right) by:JEE Main/MCQ/Medium/Matter Waves
  78. 78If the de Broglie wavelengths associated with a proton and an α\alpha-particle are equal, then the ratio of velocities of the proton and the α\alpha-particle will be:JEE Main/MCQ/Medium/Matter Waves
  79. 79Two electrons are moving with non-relativistic speeds perpendicular to each other. If corresponding de brogile wavelengths are λ1{\lambda }_{1} and λ2{\lambda }_{2}, their de brogile wavelength in the frame of reference attached to their centre of mass is:JEE Main/MCQ/Medium/Matter Waves
  80. 80A particle AA of mass mm and initial velocity vv collides with a particle BB of mass m2\dfrac{m}{2} which is at rest. The collision is head on, and elastic. The ratio of the de-Broglie wavelengths λA{\lambda }_{A} to λB{\lambda }_{B} after the collision is:JEE Main/MCQ/Medium/Matter Waves
  81. 81The de-Broglie wavelength associated with the electron in the n=4n=4 level is:JEE Main/MCQ/Medium/Matter Waves
  82. 82De-Broglie wavelength of an electron accelerated by a voltage of 50V50 \text{V} is close to (∣e∣=1.6×10−19C,me=9.1×10−31kg,h=6.6×10−34Js)\left(\left|e\right|=1.6\times {10}^{-19}C,{m}_{e}=9.1\times {10}^{-31}kg,h=6.6\times {10}^{-34}Js\right)JEE Main/MCQ/Medium/Matter Waves
  83. 83For LED's to emit light in visible region of electromagnetic light, it should have energy band gap in the range of:JEE Main/MCQ/Medium/Matter Waves
  84. 84For which of the following particles will it be most difficult to experimentally verify the de-Broglie relationship?JEE Main/MCQ/Medium/Matter Waves
  85. 85Electrons are accelerated through a potential difference V\mathrm{V} and protons are accelerated through a potential difference 4 V4 \mathrm{~V}. The de-Broglie wavelengths are λe\lambda_e and λp\lambda_p for electrons and protons respectively. The ratio of λeλp\frac{\lambda_e}{\lambda_p} is given by: (given mem_e is mass of electron and mpm_p is mass of proton).JEE Main/MCQ/Medium/Matter Waves
  86. 86Photon of frequency v\mathrm{v} has a momentum associated with it. If c\mathrm{c} is the velocity of light, the momentum isJEE Main/MCQ/Medium/Matter Waves
  87. 87The time by a photoelectron to come out after the photon strikes is approximatelyJEE Main/MCQ/Medium/Matter Waves
  88. 88If the kinetic energy of a free electron doubles. Its deBroglie wavelength changes by the factorJEE Main/MCQ/Medium/Matter Waves
  89. 89Formation of covalent bonds in compounds exhibitsJEE Main/MCQ/Medium/Matter Waves
  90. 90K1K_1 and K2K_2 be the maximum kinetic energies of photoelectrons emitted from a surface of a given material for the light of wavelength λ1\lambda_1 and λ2\lambda_2, respectively. If λ1=2λ2\lambda_1=2\lambda_2 then the work function of material is given by:JEE Main/MCQ/Medium/Photoelectric Effect
  91. 91Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
    Assertion (A): The electromagnetic wave exerts pressure on the surface on which they are allowed to fall.
    Reason (R): There is no mass associated with the electromagnetic waves.
    In the light of the above statements, choose the correct answer from the options given below :    JEE Main/MCQ/Medium/Photoelectric Effect
  92. 92Light source having wavelength 331331 nm is used to generate photo-electrons whose stopping potential is 0.20.2 V. The work function of the used metal in the experiment is α×10−19\alpha \times 10^{-19} J. The value of α\alpha is _____.
    (    h=6.62×10−34h = 6.62 \times 10^{-34} J s, e=1.6×10−19e = 1.6 \times 10^{-19} C and c=3×108c = 3 \times 10^8 m/s)    JEE Main/MCQ/Medium/Photoelectric Effect
  93. 93Match the LIST-I with LIST-II
    List-IList-IIA. Planck's constantI.     ML2T−2ML^2T^{-2}B. Stopping potentialII. T−1T^{-1}C. Work functionIII. ML2T−1ML^2T^{-1}D. Threshold frequencyIV. ML2T−3A−1ML^2T^{-3}A^{-1}
    Choose the correct answer from the options given below:    JEE Main/MCQ/Medium/Photoelectric Effect
  94. 94The graph shows variation of stopping potential VoV_o with the frequency ν\nu of the incident radiation for three photosensitive metals X1X_1, X2X_2 and X3X_3. Which metal will give out electrons with greater kinetic energy, for the same wavelength of incident radiation?
    JEE Main/MCQ/Medium/Photoelectric Effect/With diagram
  95. 95For a certain metal, when monochromatic light of wavelength λ\lambda is incident, the stopping potential for photoelectrons is 3V03V_0. When the same metal is illuminated by light of wavelength 2λ2\lambda, then the stopping potential becomes V0V_0. The threshold wavelength for photoelectric emission for the given metal is αλ\alpha\lambda. The value of α\alpha is _______.JEE Main/MCQ/Medium/Photoelectric Effect
  96. 96Number of photons of equal energy emitted per second by a 6 mW laser source operating at 663 nm is ____\_\_\_\_.
    (Given :     h=6.63×10−34 J.s\mathrm{h}=6.63 \times 10^{-34} \mathrm{~J}. \mathrm{s} and c=3×108 m/s\mathrm{c}=3 \times 10^{8} \mathrm{~m} / \mathrm{s})    JEE Main/MCQ/Medium/Photoelectric Effect
  97. 97When a light of a given wavelength falls on a metallic surface the stopping potential for photoelectrons is 3.2 V. If a second light having wavelength twice of first light is used, the stopping potential drops to 0.7 V. The wavelength of first light is ____\_\_\_\_ m. (h=6.63×10−34 J.s,e=1.6×10−19C,c=3×108 m/s)\left(\mathrm{h}=6.63 \times 10^{-34} \mathrm{~J}. \mathrm{s}, \mathrm{e}=1.6 \times 10^{-19} \mathrm{C}, \mathrm{c}=3 \times 10^{8} \mathrm{~m} / \mathrm{s}\right)JEE Main/MCQ/Medium/Photoelectric Effect
  98. 98Light is incident on a metallic plate having work function 110×10−20 J110 \times 10^{-20} \mathrm{~J}. If the produced photoelectrons have zero kinetic energy then the angular frequency of the incident light is ____\_\_\_\_ rad/s. (h=6.63×10−34 J.s)\left(\mathrm{h}=6.63 \times 10^{-34} \mathrm{~J}. \mathrm{s}\right).JEE Main/MCQ/Medium/Photoelectric Effect
  99. 99A light wave described by E=60[sin⁡(3×1015)t+sin⁡(12×1015)t]E=60\left[\sin \left(3 \times 10^{15}\right) t+\sin \left(12 \times 10^{15}\right) t\right] (in SI units) falls on a metal surface of work function 2.8 eV. The maximum kinetic energy of ejected photoelectron is (approximately) ____\_\_\_\_ eV. (h=6.6×10−34 J\left(h=6.6 \times 10^{-34} \mathrm{~J}\right.. s. and e=1.6×10−19C)\left.e=1.6 \times 10^{-19} \mathrm{C}\right)JEE Main/MCQ/Medium/Photoelectric Effect
  100. 100A small mirror of mass mm is suspended by a massless thread of length ll. Then the small angle through which the thread will be deflected when a short pulse of laser of energy EE falls normal on the mirror ( c=\mathrm{c}= speed of light in vacuum and g=\mathrm{g}= acceleration due to gravity)JEE Main/MCQ/Medium/Photoelectric Effect
  101. 101Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R\mathrm{R}
    Assertion A: In photoelectric effect, on increasing the intensity of incident light the stopping potential increases.
    Reason R : Increase in intensity of light increases the rate of photoelectrons emitted, provided the frequency of incident light is greater than threshold frequency.
    In the light of the above statements, choose the correct answer from the options given below    JEE Main/MCQ/Medium/Photoelectric Effect
  102. 102The work function of a metal is 3 eV. The color of the visible light that is required to cause emission of photoelectrons isJEE Main/MCQ/Medium/Photoelectric Effect
  103. 103The radiation pressure exerted by a 450 W light source on a perfectly reflecting surface placed at 2 m away from it, is :JEE Main/MCQ/Medium/Photoelectric Effect
  104. 104A monochromatic light is incident on a metallic plate having work function ϕ\phi. An electron, emitted normally to the plate from a point AA with maximum kinetic energy, enters a constant magnetic field, perpendicular to the initial velocity of electron. The electron passes through a curve and hits back the plate at a point BB. The distance between A and B is :
    (Given : The magnitude of charge of an electron is e and mass is     m,h\mathrm{m}, \mathrm{h} is Planck's constant and c is velocity of light. Take the magnetic field exists throughout the path of electron)    JEE Main/MCQ/Medium/Photoelectric Effect
  105. 105In an experiment with photoelectric effect, the stopping potential,JEE Main/MCQ/Medium/Photoelectric Effect
  106. 106In photoelectric effect, the stopping potential (V0)v/s\left(\mathrm{V}_0\right) \mathrm{v} / \mathrm{s} frequency (ν)(\nu) curve is plotted.
    ( h is the Planck's constant and     ϕ0\phi_0 is work function of metal )
    (A)     V0v/sν\mathrm{V}_0 \mathrm{v} / \mathrm{s} \nu is linear.
    (B) The slope of     V0v/sν\mathrm{V}_0 \mathrm{v} / \mathrm{s} \nu curve =ϕ0 h=\frac{\phi_0}{\mathrm{~h}}
    (C) h constant is related to the slope of     V0v/sν\mathrm{V}_0 \mathrm{v} / \mathrm{s} \nu line.
    (D) The value of electric charge of electron is not required to determine     hh using the V0v/sνV_0 \mathrm{v} / \mathrm{s} \nu curve.
    (E) The work function can be estimated without knowing the value of     hh.

    Choose the correct answer from the options given below :    JEE Main/MCQ/Medium/Photoelectric Effect
  107. 107In photoelectric effect an em-wave is incident on a metal surface and electrons are ejected from the surface. If the work function of the metal is 2.14 eV and stopping potential is 2 V , what is the wavelength of the em-wave ?
    (Given hc     =1242eVnm=1242 \mathrm{eVnm} where h is the Planck's constant and c is the speed of light in vaccum.)    JEE Main/MCQ/Medium/Photoelectric Effect
  108. 108A light source of wavelength λ\lambda illuminates a metal surface and electrons are ejected with maximum kinetic energy of 2 eV . If the same surface is illuminated by a light source of wavelength λ2\frac{\lambda}{2}, then the maximum kinetic energy of ejected electrons will be (The work function of metal is 1 eV )JEE Main/MCQ/Medium/Photoelectric Effect
  109. 109The work functions of cesium (Cs) and lithium (Li) metals are 1.9 eV and 2.5 eV , respectively. If we incident a light of wavelength 550 nm on these two metal surfaces, then photo-electric effect is possible for the case ofJEE Main/MCQ/Medium/Photoelectric Effect
  110. 110UV light of 4.13eV4.13 \mathrm{eV} is incident on a photosensitive metal surface having work function 3.13eV3.13 \mathrm{eV}. The maximum kinetic energy of ejected photoelectrons will be:JEE Main/MCQ/Medium/Photoelectric Effect
  111. 111Average force exerted on a non-reflecting surface at normal incidence is 2.4×10−4 N2.4 \times 10^{-4} \mathrm{~N}. If 360 W/cm2360 \mathrm{~W} / \mathrm{cm}^2 is the light energy flux during span of 1 hour 30 minutes, Then the area of the surface is:JEE Main/MCQ/Medium/Photoelectric Effect
  112. 112When UV light of wavelength 300 nm300 \mathrm{~nm} is incident on the metal surface having work function 2.13eV2.13 \mathrm{eV}, electron emission takes place. The stopping potential is:
    (Given hc     =1240eVnm=1240 \mathrm{eV} \mathrm{nm} )    JEE Main/MCQ/Medium/Photoelectric Effect
  113. 113Which of the following phenomena does not explain by wave nature of light.
    A. reflection
    B. diffraction
    C. photoelectric effect
    D. interference
    E. polarization
    Choose the most appropriate answer from the options given below:    JEE Main/MCQ/Medium/Photoelectric Effect
  114. 114In photoelectric experiment energy of 2.48eV2.48 \mathrm{eV} irradiates a photo sensitive material. The stopping potential was measured to be 0.5 V0.5 \mathrm{~V}. Work function of the photo sensitive material is :JEE Main/MCQ/Medium/Photoelectric Effect
  115. 115Which of the following statement is not true about stopping potential (V0)\left(\mathrm{V}_0\right) ?JEE Main/MCQ/Medium/Photoelectric Effect
  116. 116Given below are two statements :

    Statement I : Figure shows the variation of stopping potential with frequency     (v)(v) for the two photosensitive materials M1\mathrm{M}_1 and M2\mathrm{M}_2. The slope gives value of he\frac{\mathrm{h}}{\mathrm{e}}, where h\mathrm{h} is Planck's constant, e\mathrm{e} is the charge of electron.
    Statement II :     M2\mathrm{M}_2 will emit photoelectrons of greater kinetic energy for the incident radiation having same frequency.
    In the light of the above statements, choose the most appropriate answer from the options given below.    JEE Main/MCQ/Medium/Photoelectric Effect/With diagram
  117. 117Given below are two statements: one is labelled as Assertion A\mathbf{A} and the other is labelled as Reason R.
    Assertion A: Number of photons increases with increase in frequency of light.
    Reason R: Maximum kinetic energy of emitted electrons increases with the frequency of incident radiation.
    In the light of the above statements, choose the most appropriate answer from the options given below:    JEE Main/MCQ/Medium/Photoelectric Effect
  118. 118Which figure shows the correct variation of applied potential difference (V) with photoelectric current (I) at two different intensities of light (I1<I2)\left(\mathrm{I}_1 \lt \mathrm{I}_2\right) of same wavelengths :JEE Main/MCQ/Medium/Photoelectric Effect
  119. 119Monochromatic light of frequency 6×1014Hz6\times {10}^{14}Hz is produced by a laser. The power emitted is 2×10−3W.2\times {10}^{-3}W. How many photons per second on an average, are emitted by the source?
    (Given     h=6.63×10−34Jsh=6.63\times {10}^{-34}Js)    JEE Main/MCQ/Medium/Photoelectric Effect
  120. 120In a photoelectric effect experiment a light of frequency 1.51.5 times the threshold frequency is made to fall on the surface of photosensitive material. Now if the frequency is halved and intensity is doubled, the number of photo electrons emitted will be:JEE Main/MCQ/Medium/Photoelectric Effect
  121. 121When a metal surface is illuminated by light of wavelength λ\lambda, the stopping potential is 8V8V. When the same surface is illuminated by light of wavelength 3λ3\lambda, stopping potential is 2V2V. The threshold wavelength for this surface is :JEE Main/MCQ/Medium/Photoelectric Effect
  122. 122For the photoelectric effect, the maximum kinetic energy (Ek)\left({E}_{k}\right) of the photoelectrons is plotted against the frequency (v)(v) of the incident photons as shown in figure. The slope of the graph givesJEE Main/MCQ/Medium/Photoelectric Effect/With diagram
  123. 123If the total energy transferred to a surface in time tt is 6.48×105J6.48\times {10}^{5}J, then the magnitude of the total momentum delivered to this surface for complete absorption will be :JEE Main/MCQ/Medium/Photoelectric Effect
  124. 124The work function of a substance is 3.0eV3.0eV. The longest wavelength of light that can cause the emission of photoelectrons from this substance is approximately:JEE Main/MCQ/Medium/Photoelectric Effect
  125. 125Two sources of light emit with a power of 200W200W. The ratio of number of photons of visible light emitted by each source having wavelengths 300nm300nm and 500nm500nm respectively, will be :JEE Main/MCQ/Medium/Photoelectric Effect
  126. 126The threshold frequency of a metal with work function 6.63eV6.63eV is :JEE Main/MCQ/Medium/Photoelectric Effect
  127. 127The difference between threshold wavelengths for two metal surfaces AA and BB having work function ϕA=9eV{\phi }_{A}=9eV and ϕB=4.5eV{\phi }_{B}=4.5eV in nmnm is:
    {Given,     hc=1242eVnmhc=1242eVnm}    JEE Main/MCQ/Medium/Photoelectric Effect
  128. 128A metallic surface is illuminated with radiation of wavelength λ\lambda, the stopping potential is V0{V}_{0}. If the same surface is illuminated with radiation of wavelength 2λ2\lambda, the stopping potential becomes V04\dfrac{{V}_{0}}{4}. The threshold wavelength for this metallic surface will beJEE Main/MCQ/Medium/Photoelectric Effect
  129. 129The variation of stopping potential (V0)\left({V}_{0}\right) as a function of the frequency (ν)(\nu ) of the incident light for a metal is shown in figure. The work function of the surface is
    JEE Main/MCQ/Medium/Photoelectric Effect/With diagram
  130. 130In photoelectric effect
    A. The photocurrent is proportional to the intensity of the incident radiation.
    B. Maximum kinetic energy with which photoelectrons are emitted depends on the intensity of incident light.
    C. Max K.E. with which photoelectrons are emitted depends on the frequency of incident light.
    D. The emission of photoelectrons require a minimum threshold intensity of incident radiation.
    E. Max K.E. of the photoelectrons is independent of the frequency of the incident light.
    Choose the correct answer from the options given below:    JEE Main/MCQ/Medium/Photoelectric Effect
  131. 131The work functions of Aluminium and Gold are 4.1eV4.1eV and 5.1eV5.1eV respectively. The ratio of the slope of the stopping potential versus frequency plot for Gold to that of Aluminium isJEE Main/MCQ/Medium/Photoelectric Effect
  132. 132The threshold frequency of metal is f0{f}_{0}. When the light of frequency 2f02{f}_{0} is incident on the metal plate, the maximum velocity of photoelectron is v1{v}_{1}. When the frequency of incident radiation is increased to 5f05{f}_{0}. the maximum velocity of photoelectrons emitted is v2{v}_{2}. The ratio of v1{v}_{1} to v2{v}_{2} is:JEE Main/MCQ/Medium/Photoelectric Effect
  133. 133If the two metals AA and BB are exposed to radiation of wavelength 350nm350nm. The work functions of metals AA and BB are 4.8eVand2.2eV4.8eV\text{and}2.2eV. Then choose the correct optionJEE Main/MCQ/Medium/Photoelectric Effect
  134. 134If a source of electromagnetic radiation having power 15kW15kW produces 1016{10}^{16} photons per second, the radiation belongs to a part of spectrum is :
    (Take Planck constant     h=6×10−34Js)h=6\times {10}^{-34}Js)    JEE Main/MCQ/Medium/Photoelectric Effect
  135. 135A point source of 100W100W emits light with 55% efficiency. At a distance of 5m5m from the source, the intensity produced by the electric field component is:JEE Main/MCQ/Medium/Photoelectric Effect
  136. 136A point source of light is placed at the centre of curvature of a hemispherical surface. The source emits a power of 24W24W. The radius of curvature of hemisphere is 10cm10cm and the inner surface is completely reflecting. The force on the hemisphere due to the light falling on it is ______ ×10−8N\times {10}^{-8}N.JEE Main/Numerical/Medium/Photoelectric Effect
  137. 137A small object at rest, absorbs a light pulse of power 20mW20mW and duration 300ns300ns. Assuming speed of light as 3×108ms−13\times {10}^{8}m{s}^{-1}. The momentum of the object becomes equal to :JEE Main/MCQ/Medium/Photoelectric Effect
  138. 138The threshold wavelength for photoelectric emission from a material is 5500A∘5500A^{^{\circ}}. Photoelectrons will be emitted, when this material is illuminated with monochromatic radiation from a
    A.     75W75W infra-red lamp
    B.     10W10W infra-red lamp
    C.     75W75W ultra-violet lamp
    D.     10W10W ultra-violet lamp
    Choose the correct answer from the options given below :    JEE Main/MCQ/Medium/Photoelectric Effect
  139. 139Given below are two statements :
    Statement I : Stopping potential in photoelectric effect does not depend on the power of the light source.
    Statement II : For a given metal, the maximum kinetic energy of the photoelectron depends on the wavelength of the incident light.
    In the light of above statements, choose the most appropriate answer from the options given below.    JEE Main/MCQ/Medium/Photoelectric Effect
  140. 140From the photoelectric effect experiment, following observations are made. Identify which of these are correct
    A. The stopping potential depends only on the work function of the metal.
    B. The saturation current increases as the intensity of incident light increases.
    C. The maximum kinetic energy of a photo electron depends on the intensity of the incident light.
    D. Photoelectric effect can be explained using wave theory of light.
    Choose the correct answer from the options given below:    JEE Main/MCQ/Medium/Photoelectric Effect
  141. 141Two streams of photons, possessing energies to five and ten times the work function of metal are incident on the metal surface successively. The ratio of the maximum velocities of the photoelectron emitted, in the two cases respectively, will beJEE Main/MCQ/Medium/Photoelectric Effect
  142. 142With reference to the observations in photo-electric effect, identify the correct statements from below:
    A. The square of maximum velocity of photoelectrons varies linearly with frequency of incident light.
    B. The value of saturation current increases on moving the source of light away from the metal surface.
    C. The maximum kinetic energy of photo-electrons decreases on decreasing the power of LED (light emitting diode) source of light.
    D. The immediate emission of photo-electrons out of metal surface can not be explained by particle nature of light/electromagnetic waves.
    E. Existence of threshold wavelength can not be explained by wave nature of light/electromagnetic waves.
    Choose the correct answer from the options given below:    JEE Main/MCQ/Medium/Photoelectric Effect
  143. 143A parallel beam of light of wavelength 900nm900nm and intensity 100Wm−2100{Wm}^{-2} is incident on a surface perpendicular to the beam. The number of photons crossing 1cm21{cm}^{2} area perpendicular to the beam in one second isJEE Main/MCQ/Medium/Photoelectric Effect
  144. 144A metal exposed to light of wavelength 800nm800nm and emits photoelectrons with a certain kinetic energy. The maximum kinetic energy of photo-electron doubles when light of wavelength 500nm500nm is used. The work function of the metal is
    (Take     hc=1230eV−nmhc=1230eV-nm).    JEE Main/MCQ/Medium/Photoelectric Effect
  145. 145The electric field at a point associated with a light wave is given by
    E=200[sin⁡(6×1015)t+sin⁡(9×1015)t]Vm−1E=200\left[\sin \left(6\times {10}^{15}\right)t+\sin \left(9\times {10}^{15}\right)t\right]{Vm}^{-1}
    Given:     h=4.14×10−15eVsh=4.14\times {10}^{-15}eVs
    If this light falls on a metal surface having a work function of     2.50eV2.50eV, the maximum kinetic energy of the photoelectrons will be    JEE Main/MCQ/Medium/Photoelectric Effect
  146. 146Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
    Assertion A : The photoelectric effect does not take place, if the energy of the incident radiation is less than the work function of a metal.
    Reason R : Kinetic energy of the photoelectrons is zero, if the energy of the incident radiation is equal to the work function of a metal.    JEE Main/MCQ/Medium/Photoelectric Effect
  147. 147Let K1{K}_{1} and K2{K}_{2} be the maximum kinetic energies of photo-electrons emitted when two monochromatic beams of wavelength λ1{\lambda }_{1} and λ2{\lambda }_{2}, respectively are incident on a metallic surface. If λ1=3λ2{\lambda }_{1}=3{\lambda }_{2} then :JEE Main/MCQ/Medium/Photoelectric Effect
  148. 148The stopping potential for photoelectrons emitted from a surface illuminated by light of wavelength 6630Å6630Å is 0.42V0.42V. If the threshold frequency is x×1013sx\times {10}^{13}s, where xx is (nearest integer): (Given, speed light =3×108ms−1=3\times {10}^{8}m{s}^{-1}. Planck's constant =6.63×10−34Js=6.63\times {10}^{-34}Js)JEE Main/Numerical/Medium/Photoelectric Effect
  149. 149The light of two different frequencies whose photons have energies 3.8eV3.8eV and 1.4eV1.4eV respectively, illuminate a metallic surface whose work function is 0.6eV0.6eV successively. The ratio of maximum speeds of emitted electrons for the two frequencies respectively will be :JEE Main/MCQ/Medium/Photoelectric Effect
  150. 150When light of frequency twice the threshold frequency is incident on the metal plate, the maximum velocity of emitted electron is v1{v}_{1}. When the frequency of incident radiation is increased to five times the threshold value, the maximum velocity of emitted electron becomes v2{v}_{2}. If v2=xv1{v}_{2}=x{v}_{1}, the value of xx will be _____ .JEE Main/Numerical/Medium/Photoelectric Effect
  151. 151A monochromatic neon lamp with wavelength of 670.5nm670.5nm illuminates a photo-sensitive material which has a stopping voltage of 0.48V0.48V. What will be the stopping voltage if the source light is changed with another source of wavelength of 474.6nm474.6nm ?JEE Main/MCQ/Medium/Photoelectric Effect
  152. 152In a photoelectric experiment, increasing the intensity of incident light:JEE Main/MCQ/Medium/Photoelectric Effect
  153. 153In a photoelectric experiment, ultraviolet light of wavelength 280nm280nm is used with lithium cathode having work function ϕ=2.5eV\phi =2.5eV. If the wavelength of incident light is switched to 400nm400nm, find out the change in the stopping potential.
    (h=6.63×10−34Js,c=3×108ms−1)\left(h=6.63\times {10}^{-34}Js,c=3\times {10}^{8}{ms}^{-1}\right)    JEE Main/MCQ/Medium/Photoelectric Effect
  154. 154An electron and proton are separated by a large distance. The electron starts approaching the proton with energy 3eV3eV. The proton captures the electrons and forms a hydrogen atom in second excited state. The resulting photon is incident on a photosensitive metal of threshold wavelength 4000A4000A What is the maximum kinetic energy of the emitted photoelectron?JEE Main/MCQ/Medium/Photoelectric Effect
  155. 155A light beam of wavelength 500nm500nm is incident on a metal having work function of 1.25eV1.25eV, placed in a magnetic field of intensity BB. The electrons emitted perpendicular to the magnetic field BB, with maximum kinetic energy are bent into a circular arc of radius 30cm30cm. The value of BB is ________×10−7T\times {10}^{-7}T.
    Given     hc=20×10−26Jmhc=20\times {10}^{-26}Jm, the mass of the electron=9×10−31kg=9\times {10}^{-31}kg.    JEE Main/Numerical/Medium/Photoelectric Effect
  156. 156When radiation of wavelength λ\lambda is incident on a metallic surface, the stopping potential of ejected photoelectrons is 4.8V4.8V. If the same surface is illuminated by radiation of double the previous wavelength, then the stopping potential becomes 1.6V1.6V. The threshold wavelength of the metal is:JEE Main/MCQ/Medium/Photoelectric Effect
  157. 157A certain metallic surface is illuminated by monochromatic radiation of wavelength λ\lambda. The stopping potential for photoelectric current for this radiation is 3V0.3{V}_{0}. If the same surface is illuminated with a radiation of wavelength 2λ,2\lambda , the stopping potential is V0.{V}_{0}. The threshold wavelength of this surface for photoelectric effect is___________λ.\lambda .JEE Main/Numerical/Medium/Photoelectric Effect
  158. 158Two identical photocathodes receive the light of frequencies f1{f}_{1} and f2{f}_{2} respectively. If the velocities of the photo-electrons coming out are v1{v}_{1} and v2{v}_{2} respectively, thenJEE Main/MCQ/Medium/Photoelectric Effect
  159. 159The stopping potential in the context of photoelectric effect depends on the following property of incident electromagnetic radiation:JEE Main/MCQ/Medium/Photoelectric Effect
  160. 160Two stream of photons, possessing energies equal to twice and ten times the work function of metal are incident on the metal surface successively. The value of ratio of maximum velocities of the photoelectrons emitted in the two respective cases is x:3x:3 The value of xx isJEE Main/Numerical/Medium/Photoelectric Effect
  161. 161The stopping potential for electrons emitted from a photosensitive surface illuminated by light of wavelength 491nm491nm is 0.710V.0.710V. When the incident wavelength is changed to a new value, the stopping potential is 1.43V.1.43V. The new wavelength is :JEE Main/MCQ/Medium/Photoelectric Effect
  162. 162Given below are two statements:
    Statement     I:I: Two photons having equal linear momenta have equal wavelengths.
    Statement     II:II: If the wavelength of the photon is decreased, then the momentum and energy of a photon will also decrease.
    In the light of the above statements, choose the correct answer from the options given below.    JEE Main/MCQ/Medium/Photoelectric Effect
  163. 163The surface of a metal is illuminated alternately with photons of energies E1=4eV{E}_{1}=4eV and E2=2.5eV{E}_{2}=2.5eV respectively. The ratio of maximum speeds of the photoelectrons emitted in the two cases is 2.2. The work function of the metal in (eV)(eV) is..........JEE Main/Numerical/Medium/Photoelectric Effect
  164. 164In a photoelectric effect experiment, the graph of stopping potential VV versus reciprocal of wavelength obtained is shown in the figure. As the intensity of incident radiation is increased :
    JEE Main/MCQ/Medium/Photoelectric Effect/With diagram
  165. 165Given figure shows few data points in a photo-electric effect experiment for a certain metal. The minimum energy for ejection of electrons from its surface is: (Planck's constant h=6.62×10–34J.sh=6.62\times {10}^{–34}\text{J.s})
    JEE Main/MCQ/Medium/Photoelectric Effect/With diagram
  166. 166When the wavelength of radiation falling on a metal is changed from 500nmto200nm500nmto200nm, the maximum kinetic energy of the photoelectrons becomes three times larger. The work function of the metal is close to:JEE Main/MCQ/Medium/Photoelectric Effect
  167. 167When radiation of wavelength AA is used to illuminate a metallic surface, the stopping potential is VV. When the same surface is illuminated with radiation of wavelength 3A3A, the stopping potential is V4\dfrac{V}{4}. If the threshold wavelength for the metallic surface is nλn\lambda then value of nn will be :JEE Main/Numerical/Medium/Photoelectric Effect
  168. 168A beam of electromagnetic radiation of intensity 6.4×10−5W/cm26.4\times {10}^{-5}\text{W}/{\text{cm}}^{2} is comprised of wavelength, λ=310nm\lambda =310nm . It falls normally on a metal (work function ϕ=2eV\phi =2eV ) of surface area of 1cm21{cm}^{2} . If one in 103{10}^{3} photons ejects an election, total number of electrons ejected in 1s1s is 10x{10}^{x} . (hc=1240eVnm,1eV=1.6×10−19J),\left(hc=1240eVnm,1eV=1.6\times {10}^{-19}J\right), then xx is ___________JEE Main/Numerical/Medium/Photoelectric Effect
  169. 169The stopping potential Vo{V}_{o} (in volt) as a function of frequency (v)(v) for a sodium emitter, is shown in the figure. The work function of sodium, form the data plotted in the figure, will be:
    (Given: Planck’s constant     (h)=6.63×10−34Js\left(h\right)=6.63\times {10}^{-34}Js , electron charge (e)(\text{e}) =1.6×10−19C)=1.6\times {10}^{-19}C)
    JEE Main/MCQ/Medium/Photoelectric Effect/With diagram
  170. 170A 2mW2mW laser operates at a wavelength of 500nm500nm . The number of photons that will be emitted per second is:
    [Given Planck's constant     h=6.6×10−34Js,h=6.6\times {10}^{-34}Js, speed of light c=3.0×108m/sc=3.0\times {10}^{8}m/s ]    JEE Main/MCQ/Medium/Photoelectric Effect
  171. 171Light is incident normally on a completely absorbing surface with an energy flux of 25Wcm−225Wc{m}^{-2} . If the surface has an area of 25cm225c{m}^{2} , the momentum transferred to the surface in 40min\text{40} \text{min} time duration will be:JEE Main/MCQ/Medium/Photoelectric Effect
  172. 172In a photoelectric effect experiment, the threshold wavelength of light is380nm380nm . If the wavelength of incident light is260nm260nm , the maximum kinetic energy of emitted electrons will be
    Given     EE (in eVeV ) =1237λ(innm)=\dfrac{1237}{\lambda (innm)}    JEE Main/MCQ/Medium/Photoelectric Effect
  173. 173The electric field of light wave is given as \vec{E}={10}^{–3}\cos ⁡\left(\dfrac{2\pi x}{5\times {10}^{–7}}-2\pi \times 6\times {10}^{14}t\right)x^{^}\dfrac{N}{C} . This light falls on a metal plate of work function 2eV2eV . The stopping potential of the photo-electrons is:
    Given,     EE (in eVeV ) =12375λ(inA˚)=\dfrac{12375}{\lambda (inÅ)}    JEE Main/MCQ/Medium/Photoelectric Effect
  174. 174When a certain photosensitive surface is illuminated with a monochromatic light of frequency ν,\nu , the stopping potential of the photo current is −V02.-\dfrac{{V}_{0}}{2}. When the surface is illuminated by monochromatic light of frequency ν2,\dfrac{\nu }{2}, the stopping potential is −V0.-{V}_{0}. The threshold frequency for photoelectric emission isJEE Main/MCQ/Medium/Photoelectric Effect
  175. 175In a photoelectric experiment, the wavelength of the light incident on a metal is changed from 300nm300 \mathrm{nm} to 400nm400 \mathrm{nm}. The decrease in the stopping potential is close to :

    (hce=1240nm−V)\left(\frac{\mathrm{hc}}{\mathrm{e}}=1240 \mathrm{nm}-\mathrm{V}\right)    JEE Main/MCQ/Medium/Photoelectric Effect
  176. 176A metal plate of area 1×10−4m21\times {10}^{-4}{m}^{2} is illuminated by a radiation of intensity 16milliWm216\dfrac{milliW}{{m}^{2}} . The work function of the metal is 5eV.5eV. The energy of the incident photons is 10eV10eV and only 1010% of it produces photo electrons. The number of emitted photo electron per second and their maximum energy, respectively, will be: [1eV=1.6×10−19J]\left[1 eV=1.6\times {10}^{-19}J\right]JEE Main/MCQ/Medium/Photoelectric Effect
  177. 177The magnetic field associated with a light wave is given, at the origin, by B=B0[sin⁡⁡(3.14×107)ct+sin⁡⁡(6.28×107)ct].B={B}_{0}\left[\sin ⁡\left(3.14\times {10}^{7}\right)ct+\sin ⁡\left(6.28\times {10}^{7}\right)ct\right]. If this light falls on a silver plate having a work function of 4.7eV,4.7eV, what will be the maximum kinetic energy of the photoelectrons?

    (c=3×108ms−1,h=6.6×10−34Js)(c=3\times {10}^{8} m {s}^{-1},h=6.6\times {10}^{-34} J s)    JEE Main/MCQ/Medium/Photoelectric Effect
  178. 178The surface of certain metal is first illuminated with light of wavelength λ1=350nm{\lambda }_{1}=350nm and then, by a light of wavelength λ2=540nm.{\lambda }_{2}=540nm. It is found that the maximum speed of the photoelectrons in the two cases differ by a factor of 22. The work function of the metal (in eVeV) is close to

    (Energy of photon     =1240λ(innm)eV=\dfrac{1240}{\lambda \left(innm\right)}eV )    JEE Main/MCQ/Medium/Photoelectric Effect
  179. 179A laser light of wavelength 660nm660nm is used to weld Retina detachment. If a laser pulse of width 60ms60ms and power 0.5kW0.5kW is used, the approximate number of photons in the pulse are (Take Planck's Constant, h=6.62×10−34Js)h=6.62\times {10}^{-34}Js)JEE Main/MCQ/Medium/Photoelectric Effect
  180. 180The maximum velocity of the photoelectrons emitted from the surface is vv when light of frequency nn falls on a metal surface. If the incident frequency is increased to 3n3n, the maximum velocity of the ejected photoelectrons will be:JEE Main/MCQ/Medium/Photoelectric Effect
  181. 181A photoelectric surface is illuminated successively by monochromatic light of wavelengths λandλ2.\lambda and\dfrac{\lambda }{2}. If the maximum kinetic energy of the emitted photoelectrons in the second case is 3 times that in the first case, the work function of the surface is :JEE Main/MCQ/Medium/Photoelectric Effect
  182. 182When photons of wavelength λ1{\lambda }_{1} are incident on an isolated sphere, the corresponding stopping potential is found to be VV. When photons of wavelength λ2{\lambda }_{2} are used, the corresponding stopping potential was thrice that of the above value. If light of wavelength λ3{\lambda }_{3} is used then find the stopping potential for this case:JEE Main/MCQ/Medium/Photoelectric Effect
  183. 183Radiation of wavelength λ\lambda is incident on a photocell. The fastest emitted photoelectron has a speed vv. If the wavelength is changed to 3λ4\dfrac{3\lambda }{4}, the speed of the fastest emitted photoelectron will beJEE Main/MCQ/Medium/Photoelectric Effect
  184. 184A beam of light has two wavelengths of 4972A˚4972 Å and 6216A˚6216 Å with a total intensity of 3.6×10−33.6 \times 10^{-3} Wm−2\mathrm{Wm}^{-2} equally distributed among the two wavelengths. The beam falls normally on an area of 1 cm21 \mathrm{~cm}^2 of a clean metallic surface of work function 2.3eV2.3 \mathrm{eV}. Assume that there is no loss of light by reflection and that each capable photon ejects one electron. The number of photoelectrons liberated in 2 s2 \mathrm{~s} is approximately:JEE Main/MCQ/Medium/Photoelectric Effect
  185. 185A copper ball of radius 1 cm1 \mathrm{~cm} and work function 4.47 eV4.47 \mathrm{~eV} is irradiated with ultraviolet radiation of wavelength 2500 A˚2500 ~Å. The effect of irradiation results in the emission of electrons from the ball. Further the ball will acquire charge and due to this there will be a finite value of the potential on the ball. The charge acquired by the ball is :JEE Main/MCQ/Medium/Photoelectric Effect
  186. 186In an experiment on photoelectric effect, a student plots stopping potential V0\mathrm{V}_0 against reciprocal of the wavelength λ\lambda of the incident light for two different metals A\mathrm{A} and B\mathrm{B}. These are shown in the figure.


    Looking at the graphs, you can most appropriately say that:    JEE Main/MCQ/Medium/Photoelectric Effect/With diagram
  187. 187The anode voltage of a photocell is kept fixed. The wavelength λ\lambda of the light falling on the cathode is gradually changed. The plate current I\text{I} of the photocell varies as follows :JEE Main/MCQ/Medium/Photoelectric Effect
  188. 188Photoelectrons are ejected from a metal when light of frequency vv falls on it. Pick out the wrong statement from the following.JEE Main/MCQ/Medium/Photoelectric Effect
  189. 189This 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 metallic surface is irradiated by a monochromatic light of frequency     v>v0v\gt v_0 (the threshold frequency). If the incident frequency is now doubled, the photocurrent and the maximum kinetic energy are also doubled.
    Statement 2: The maximum kinetic energy of photoelectrons emitted from a surface is linearly dependent on the frequency of the incident light. The photocurrent depends only on the intensity of the incident light.    JEE Main/MCQ/Medium/Photoelectric Effect
  190. 190This question has Statement −1-1 and Statement −2-2. Of the four choices given after the statements, choose the one that best describes the two statements.
    Statement-1 : A metallic surface is irradiated by a monochromatic light of frequency     v>v0v\gt v_0 (the threshold frequency). The maximum kinetic energy and the stopping potential are Kmax⁡\mathrm{K}_{\max } and V0\mathrm{V}_0 respectively. If the frequency incident on the surface doubled, both the Kmax⁡\mathrm{K}_{\max } and V0\mathrm{V}_0 are also doubled.
    Statement-2 : The maximum kinetic energy and the stopping potential of photoelectrons emitted from a surface are linearly dependent on the frequency of incident light.    JEE Main/MCQ/Medium/Photoelectric Effect
  191. 191Statement-1 : When ultraviolet light is incident on a photocell, its stopping potential is V0V_0 and the maximum kinetic energy of the photoelectrons is Kmax⁡\mathrm{K}_{\max }. When the ultraviolet light is replaced by X−\mathrm{X}- rays, both V0\mathrm{V}_0 and Kmax⁡\mathrm{K}_{\max } increase.
    Statement-2 : Photoelectrons are emitted with speeds ranging from zero to a maximum value because of the range of frequencies present in the incident light.
    Of the four choices given after the statements, choose the one that best describes the two statements.    JEE Main/MCQ/Medium/Photoelectric Effect
  192. 192The surface of a metal is illuminated with the light of 400 nm400 \mathrm{~nm}. The kinetic energy of the ejected photoelectrons was found to be 1.68eV1.68 \mathrm{eV}. The work function of the metal is (hc=1240eVnm)(\mathrm{hc}=1240 \mathrm{eV} \mathrm{nm})JEE Main/MCQ/Medium/Photoelectric Effect
  193. 193The anode voltage of a photocell is kept fixed. The wavelength λ\lambda of the light falling on the cathode is gradually changed. The plate current I\mathrm{I} of the photocell varies as follows :JEE Main/MCQ/Medium/Photoelectric Effect
  194. 194The threshold frequency for a metallic surface corresponds to an energy of 6.2eV6.2 \mathrm{eV}, and the stopping potential for a radiation incident on this surface 5 V5 \mathrm{~V}. The incident radiation lies inJEE Main/MCQ/Medium/Photoelectric Effect
  195. 195A photocell is illuminated by a small bright source placed 1 m1 \mathrm{~m} away. When the same source of light is placed 12 m\frac{1}{2} \mathrm{~m} away, the number of electrons emitted by photo cathode wouldJEE Main/MCQ/Medium/Photoelectric Effect
  196. 196The work function of a substance is 4.0eV4.0 \mathrm{eV}. Then longest wavelength of light that can cause photoelectron emission from this substance approximatelyJEE Main/MCQ/Medium/Photoelectric Effect
  197. 197According to EInstein's photoelectric equation, the plot of the kinetic energy of the emitted photo electrons from a metal Vs\mathrm{V}_{\mathrm{s}} the frequency, of the incident radiation gives straight line whose slopeJEE Main/MCQ/Medium/Photoelectric Effect
  198. 198A radiation of energy EE falls normally on a perfectly reflecting surface. The momentum transferred to the surface isJEE Main/MCQ/Medium/Photoelectric Effect
  199. 199Two identical photocathodes receive light of frequencies f1\mathrm{f}_1 and f2\mathrm{f}_2. If the velocities of the photo electrons (of mass m\mathrm{m} ) coming out are respectively v1\mathrm{v}_1 and v2\mathrm{v}_2, thenJEE Main/MCQ/Medium/Photoelectric Effect
  200. 200Sodium and copper have work functions 2.3eV2.3 \mathrm{eV} and 4.5eV4.5 \mathrm{eV} respectively. Then the ratio of the wave lengths is nearest toJEE Main/MCQ/Medium/Photoelectric Effect

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