JEE Main 2019 — Electromagnetic Induction Question with Solution
From: JEE Main 2019 (Online) 11th January Evening Slot
Question
A copper wire is wound on a wooden frame, whose shape is that of an equilateral triangle. If the linear
dimension of each side of the frame is increased by a factor of 3, keeping the number of turns of the coil per
unit length of the frame the same, then the self inductance of the coil:
Choose an option
Show full solutionCorrect option: D
Correct answer
Dincreases by a factor of 3
Step-by-step explanation
Total length L will remain constant
L = (3a) N (N = total turns)
and length of winding = (d) N
(d = diameter of wire)
self inductance = 0n2A
= 0n2 dN
a2 N a
So self inductance will become 3 times
L = (3a) N (N = total turns)
and length of winding = (d) N
(d = diameter of wire)
self inductance = 0n2A
= 0n2 dN
a2 N a
So self inductance will become 3 times
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This is a previous-year question from JEE Main 2019, 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.