What is the device to protect equipments from the electric shock?

Question

What is the device to protect equipments from the electric shock?

1. A. Fuse (Correct answer)
2. B. Generator
3. C. Motor
4. D. Current controller

Correct Answer

Option A — Fuse

Detailed Solution & Explanation

The correct answer is Fuse.

Key Points

• A fuse is the safety device used to protect electrical equipment and wiring from damage caused by excessive current, as occurs during a short circuit or overloading.
• A fuse consists of a short piece of wire made from an alloy of tin and lead, chosen because it has a low melting point and high resistivity.
• It is always connected in series with the live wire.
• When the current exceeds the rated value, the heat produced according to H = I²Rt melts the fuse wire, breaking the circuit and cutting off the supply.
• In modern installations the fuse is increasingly replaced by the Miniature Circuit Breaker (MCB), which trips electromagnetically and can simply be reset rather than replaced.

Exam Tip

• distinguish the protective devices by purpose — a fuse/MCB protects against excess current, while earthing protects the user from electric shock by providing a low-resistance path for leakage current to the ground.
• The earth wire is conventionally green, the live wire red or brown, and the neutral black or blue.

प्रश्न (हिन्दी में)

उपकरणों को विद्युत आघात से बचाने वाली युक्ति है:

1. A. फ्यूज
2. B. जनित्र
3. C. मोटर
4. D. धारा नियंत्रक