What could be the possible reason for the torch bulb not glowing even when the circuit appears to be complete?

Question

A student made a circuit by using an electric cell, a switch, a torch bulb (fitted in the bulb holder) and copper connecting wires. When he turned on the switch, the torch bulb did not glow at all. The student checked the circuit and found that all the wire connections were tight.

What could be the possible reason for the torch bulb not glowing even when the circuit appears to be complete?

Answer 1

The possible reasons so that even at switch ‘ON’ position the bulb is not glowing are:

1. The cell may be discharge 

2. The bulb may be fused. 

3. The wire may be broken from inside 

4. The connection may be loose.