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Concepts Of Physics MCQ Edition [Volume 2]PhysicsElectromagnetic Induction

When the current in an inductor changes from 2.5 A in one direction to the same value in the opposite direction over a period of 0.1 s , an average emf of 20 V is induced. Determine the self-inductance of the inductor.

Options

  1. A4.0 H
  2. B0.8 H
  3. C0.4 H
  4. D0.2 H

Correct answer

C. 0.4 H

Step-by-step solution

The average induced emf in an inductor is given by the formula: |E| = L | I t | Given initial current I₁ = 2.5 A and final current I₂ = -2.5 A , the change in current is: I = I₂ - I₁ = -2.5 - 2.5 = -5.0 A The time interval is t = 0.1 s and the average induced emf is |E| = 20 V . Substituting these values into the formula: 20 = L | -5.0 0.1 | 20 = L 50 L = 20 50 = 0.4 H

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