Magnetic Properties of Matter

JEE Main level, single correct, medium

35 of 57

Question 35 of 57

A magnetic needle of magnetic moment 6.7×10−2Am26.7\times {10}^{-2}A{m}^{2} and moment of inertia 7.5×10−6kgm27.5\times {10}^{-6}kg{m}^{2} is performing simple harmonic oscillations in a magnetic field of 0.01T0.01T. Time taken for 1010 complete oscillations is:

Show answer and solution

Answer: (B) 6.65s6.65s

Time period of oscillating magnetic needle is T=2πIMBT=2\pi \sqrt{\dfrac{I}{MB}}

=2π7.5×10−66.7×10−2×0.01sec⁡=2\pi \sqrt{\dfrac{7.5\times {10}^{-6}}{6.7\times {10}^{-2}\times 0.01}}\sec

=0.6647sec⁡=0.6647\sec

Time for oscillations, t=10T=6.647sec⁡⁡=6.65sec⁡t=10T=6.647\sec ⁡=6.65\sec

JEE Main question paper PDF

Open a shift to read the full paper on this page, or download it.

JEE Main 2025 Apr 2 Shift 1 question paper

Open Download PDF

Opening paper…

Explain it as a whiteboard videoStep-by-step, in Hinglish or English. Your first video needs no login.Solved it on paper but got it wrong?Upload a photo of your working. Mistake Doctor marks the exact line that broke.

More Physics practice

JEE Main Physics practice question on Magnetic Properties of Matter (Magnetic Equipments), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.