Question

A fuse is made up of

• A. thin wire of high melting point
• B. thin wire of low melting point
• C. thick wire of high melting point
• D. thick wire of low melting point

Answer 1

The Correct Option is B

A fuse in an electrical circuit is a safety device designed to protect the circuit from excessive current. When the current exceeds a certain level, the fuse 'blows' or melts, breaking the circuit and stopping the flow of electricity. This action prevents damage to the electrical components or even fires.

The construction of a fuse involves using a thin wire of low melting point. The reasoning behind this is tied to the operational principle of the fuse:

• When an excessive current flows through the circuit, the electrical energy generates heat according to the formula Q = I²Rt, where Q is the heat energy, I is the current, R is the resistance, and t is the time.
• The wire in the fuse is intentionally thin, making its resistance higher, and thus, it heats up more quickly when the current increases.
• The wire is made from a material with a low melting point. This ensures that the fuse wire melts when the temperature exceeds the safe limit due to excessive current, ensuring rapid disconnection of the circuit.

This design facilitates efficient protection of the electrical setup by promptly interrupting overcurrent conditions before they can cause harm.

Answer 2

A fuse is a safety device used in electrical circuits to prevent damage due to overcurrent. It is made of a thin wire that has a low melting point. When the current exceeds a safe limit, the fuse wire melts due to the heat produced, and thus breaks the circuit to stop the flow of electricity. Therefore, a fuse must be made of a thin wire of low melting point.

Final Answer: thin wire of low melting point