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CUET · PHYSICS · PYQ PAPER 2025

In a coil, the current is changed from 12 A to 24 A in 1 s. The self-induced emf of the coil is 24 V. The change in energy in the coil is

  1. A 432 J
  2. B 360 J
  3. C 216 J
  4. D 108 J
Verified Solution

Answer & Solution

Correct Answer

(A) 432 J

Step-by-step Solution

Detailed explanation

\(L = \frac{|\mathcal{E}|}{|\Delta I / \Delta t|}\) \(L = \frac{24}{(24-12)/1} = \frac{24}{12} = 2 \, \text{H}\) \(\Delta U = \frac{1}{2} L (I_f^2 - I_i^2)\) \(\Delta U = \frac{1}{2} (2) (24^2 - 12^2) = 1 (576 - 144) = 432 \, \text{J}\)