Question

(iii)What is the main purpose of earthing an electrical appliance?

Hint:

Always check that appliances are properly earthed, especially when they involve metallic parts that could become live. A good earthing system is vital for safety.

Answer 1

Earthing is a critical safety feature in electrical systems that prevents electric shock and damage to electrical appliances. The main purpose of earthing an electrical appliance is to provide a safe path for the flow of electric current to the ground, in case of faults like short circuits or leakage of current. This is achieved by connecting the metal parts of the appliance (which might become live due to a fault) to the earth through an earth wire. The primary reasons for earthing are: 1. Preventing Electric Shock: If there is a fault in the appliance, such as a live wire touching a metal part of the appliance, the metal part could become live. If someone touches it, they may receive an electric shock. Earthing ensures that the electric current is safely directed to the ground, minimizing the risk of shock. 2. Protecting Appliances: Earthing helps to protect electrical appliances from damage due to electrical faults. Without earthing, electrical surges or faults could cause irreparable damage to the appliance or its components. 3. Fire Prevention: Without earthing, a faulty appliance can accumulate excess charge, leading to the risk of overheating and fires. By directing excess current into the earth, earthing prevents the accumulation of excess electrical energy in the appliance, thereby reducing fire hazards. 4. Maintaining Safety Standards: Earthing is a legal requirement in most countries to ensure the safety of electrical systems in homes and industries. It guarantees that all appliances and electrical systems conform to safety regulations. By ensuring that faulty electrical currents are safely discharged into the ground, earthing helps in avoiding electrical accidents and ensuring the safety of both people and appliances.