JEE Main 2018PhysicsMagnetic Effects of CurrentEasyMCQ

JEE Main 2018Magnetic Effects of Current Question with Solution

JEE Main 2018 (08 Apr)

Question

An electron, a proton and an alpha particle having the same kinetic energy are moving in circular orbits of radii re, rp, rα respectively in a uniform magnetic field B. The relation between re, rp, rα is:

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Show full solutionCorrect option: C
Correct answer
Cre<rp=rα

Step-by-step explanation

r=mVqB=2mKqBrmq. For electron, re=kmee Where, me is the mass of an electron. m=the mass of a proton. For alpha particles, rα=k4m2e=kmeq=charge on proton. For proton, rp=kme, so, re<rp=rα.

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About this question

This is a previous-year question from JEE Main 2018, 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.