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Saturday, 31 October

JEE Main 2022 · PhysicsMultiple choiceSingle correctHardMulti-step

JEE Main 29 July 2022, Shift 1, Physics Q44

Question 44 of 90 in this shift, Physics question 14 of 30, Section A.

A coil of inductance 1 H and resistance 100 Ω\Omega is connected to a battery of 6 V. Determine approximately : (a) The time elapsed before the current acquires half of its steady - state value. (b) The energy stored in the magnetic field associated with the coil at an instant 15 ms after the circuit is switched on. (Given ln2 = 0.693, e−3/2e^{-3/2} = 0.25)
  1. (1)t = 10 ms; U = 2 mJ
  2. (2)t = 10 ms; U = 1 mJ
  3. (3)t = 7 ms; U = 1 mJOfficial answer
  4. (4)t = 7 ms; U = 2 mJ

Official answer

Option 3

NTA final key.

Chapter
Electromagnetic Induction
Topic
Lenz's Law
Idea tested
Opposing Current Growth and Decay

Same topic in other shifts

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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.