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CUET · PHYSICS · PYQ PAPER 2025

A 12 V battery is connected to a \( 6 \text{ } \Omega, 10 \text{ H} \) coil, through a closed switch. The switch is suddenly opened in 1 ms. The average induced emf across the coil will be

  1. A 10,000 V
  2. B 20,000 V
  3. C 15,000 V
  4. D 30,000 V
Verified Solution

Answer & Solution

Correct Answer

(B) 20,000 V

Step-by-step Solution

Detailed explanation

\( I = \frac{V}{R} = \frac{12 \text{ V}}{6 \text{ } \Omega} = 2 \text{ A} \) \( \text{emf} = -L \frac{\Delta I}{\Delta t} = -(10 \text{ H}) \frac{(0 - 2 \text{ A})}{1 \times 10^{-3} \text{ s}} = 20,000 \text{ V} \)