JEE Main 2018 — Electromagnetic Induction Question with Solution
From: JEE Main 2018 (Online) 15th April Evening Slot
Question
At the center of a fixed large circular coil of radius R, a much smaller circular coil of radius r is placed. The two coils are concentric and are in the same plane. The larger coil carries a current I. The smaller coil is set to rotate with a constant angular velocity about an axis along their common diameter. Calculate the emf induced in their smaller coil after a time t of its start of rotation.
Choose an option
Show full solutionCorrect option: A
Correct answer
A r2 sin t
Step-by-step explanation
We know that electric flux
Now, is magnetic field due to circular coil of radius R and is area of circular coil of radius r. Therefore,
Now induced emf
Practice this on the real CBT interface
Solve this JEE Main question (and the rest of the Electromagnetic Induction 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 2018, covering the Electromagnetic Induction 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.