JEE Main 2020 · PhysicsNumerical answerNumerical valueEasyCalculation

JEE Main 9 January 2020, Shift 1, Physics Q24

Question 24 of 75 in this shift, Physics question 24 of 25, Section B.

In a fluorescent lamp choke (a small transformer) 100 V of reverse voltage is produced when the choke current changes uniformly from 0.25 A to 0 in a duration of 0.025 ms. The self-inductance of the choke (in mH) is estimated to be __________.

Official answer

10.00

NTA final key (Jan 2020).

Chapter: Electromagnetic Induction
Topic: Inductance
Idea tested: Self-Inductance and Back EMF

Same idea in other shifts

Asked 6× in all

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Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.