JEE Main 2020PhysicsMagnetic Effects of CurrentMediumMCQ

JEE Main 2020Magnetic Effects of Current Question with Solution

JEE Main 2020 (09 Jan Shift 2)

Question

A small circular loop of conducting wire has radius a and carries current I. It is placed in a uniform magnetic field B perpendicular to its plane such that when rotated slightly about its diameter and released, it starts performing simple harmonic motion of time period T. The mass of the loop is m then:

Choose an option

Show full solutionCorrect option: C
Correct answer
CT=2πmiB

Step-by-step explanation

τ=MBsinθ=Iα
πR2iBθ=mR22α
ω=2πiBm=2πT;T=2πmiB

Practice this on the real CBT interface

Solve this JEE Main question (and the rest of the Magnetic Effects of Current chapter) on PrepSharp's TCS iON-style CBT player — with timer, bookmarks and session analytics.

Solve interactively →

About this question

This is a previous-year question from JEE Main 2020, covering the Magnetic Effects of Current chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.