The correct option is
A is true but R is false
.Explanation
Earthing is a critical safety measure in domestic electrical circuits. It involves connecting the metallic casing of electrical appliances to the ground using a specific wire, known as the earth wire. This ensures that the appliance remains safe to touch even in the event of an insulation failure.
Statement-wise Analysis:
- Assertion (A): Correct. The metallic body of electric appliances (such as refrigerators, irons, and toasters) is connected to the earth wire. This connection ensures that if the live wire accidentally touches the metallic body due to insulation damage, the current is transferred to the earth rather than passing through the user’s body.
- Reason (R): Incorrect. The earth wire is designed to provide a low resistance path for the electric current, not a high resistance path. By offering a path of least resistance, the earth wire ensures that any leakage current flows instantly to the ground. This surge in current is typically sufficient to blow the fuse or trip the circuit breaker, thereby disconnecting the faulty appliance from the power supply and preventing electric shocks.
Key Takeaway:
The primary function of the earth wire is to provide a low-resistance path to the ground, ensuring that the metallic body of an appliance remains at zero potential to protect the user from fatal electric shocks.