Assertion (A): When a circuit having large inductance is switched off sparking occurs at the switch.
Reason (R): Emf induced in an inductor is given by \( |\text{E}| = \text{L} |\frac{\text{di}}{\text{dt}}| \).
(1) Both (A) & (R) are true and the (R) is the correct explanation of the (A)
(2) Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(3) (A) is true but (R) is false
(4) Both (A) and (R) are false
Solution:
When a circuit with large inductance is switched off, \( \text{di/dt} \) is very large. This induces a large \( \text{EMF} = \text{L di/dt} \) across the inductor, causing sparking.
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