Question

Observe the following circuits carefully. In which circuit will the bulb glow.

• A.
• B.
• C.
• D.

Answer 1

Answer: (B), (D)

Explanation for the correct options

Option (D)

1. Steel is a metal alloy and a good conductor for current conduction.
2. It can close the circuit gap.
3. The bulb in the circuit, where the gap connected by steel will glow.

Option (B)

1. Nail is made of iron. Iron is an excellent current conductor.
2. It can close the circuit gap. And in this circuit, the bulb will glow.

Explanation for the incorrect options

Option (A) and option (C)

1. Coal and eraser are bad conductor of electricity.
2. The bulb in the circuit, where the gap connected by coal and eraser does not glow.

So, option (B) and option (D) is correct.