Question

When an electric current flows through a copper wire AB as shown in the figure, the wire

Fig. \( 14.1 \)

• A. Deflects a magnetic needle placed near it.
• B. Becomes red hot.
• C. Gives an electric shock.
• D. Behaves like a fuse

Answer 1

The correct option is A

Deflects a magnetic needle placed near it.

The explanation for the correct option

Magnetic field

1. Magnetic field is the region around a magnetic material or a current-carrying wire, where the magnetic force acts.
2. When a wire carries some current, a magnetic field is generated around the wire.
3. Due to the magnetic effect, when a magnetic needle is placed near it, it will get deflected.
4. Hence, option (A) is correct.

The explanation for the incorrect options

Heating effect

1. Heating effect generally takes place in a resistive circuit.
2. When electrons flow through a resistive circuit, due to the resistance of the circuit, the electrons bump into atoms outside of the wire.
3. As a result, the wire becomes hot.
4. Since the current is flowing through the wire without much resistance, the heating effect will not be seen in the wire.
5. Hence, option (B) is incorrect.

Electrical shock

1. Electrical shock occurs when a person comes nearby an electrical source.
2. Since the circuit is complete, and the wires are well insulated from the outside, electrical shock will not occur in this scenario.
3. Hence, option (C) is incorrect.

Fuse

1. Fuse is a small piece of wire, having a low melting point.
2. It is used to melt and break the circuit, in necessary conditions.
3. Since, the material of the wire is copper, and the length of the wire is long, it can be said that the wire does not act as fuse.
4. Hence, option (D) is incorrect.

Therefore, option (A) is the only correct option.