Question

Figure below shows a bulb connected in an electrical circuit.

1. When the key is switched ON the bulb obtains maximum glow only after a shorter interval of time which property of the solenoid is responsible for the delay?

• Self-induction
• Mutual Induction
• Inductive reactance
• None of the above

2. If the flux linked with the solenoid changes from 0 to 1 weber in 2 sec. Find the induced emf in the solenoid.

3. If the 3v battery is replaced by an AC source with the key closed, what will be observation? Justify your answer.

Answer 1

1. Self-induction

2. \(\frac{d\phi}{dt}\) = \(\frac{1}{2}\) = = 0.5V.

3. When AC is connected the brightness of bulb will be decreased. This is due to the back emf in the circuit.