Question

In the circuit shown in figure bulb will become suddenly bright if:

• A. contact is made or broken
• B. contact is made
• C. contact is broken
• D. Would not become bright

Answer 1

Answer: (C)

contact is broken

When a circuit is broken$,$ the induced $e.m.f$ is largest$.$

Hence,

option $C$ is correct answer.

When contact is broken, current in the circuit decreases. To oppose this inductor releases current and emf is induced. This induced emf is having high value hence bulb will become suddenly bright.