Question

Assertion :Fuse wire must have high resistance and low melting point. Reason: Fuse is used for small current flow only.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Assertion is incorrect but Reason is correct

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

The main object of using fuse wire in electric circuit is to provide protection against short circuit or overload current. This means it protects the circuit from huge amount of current flow as it cause the damage to the circuit.
The fuse wire select such a way that it burns and break the circuit when large current passes. For this purpose the material used as fuse wire should have high resistance and low melting point.

Due to high resistance the wire heats up quickly, when huge current flows. The temperature around the fuse wire rapidly rises, when it reaches the melting point of the material it burns and protects the circuits.
High resistance and low melting point are responsible to the quick response of the fuse wire towards the current.
The common material used as fuse wire is an alloy of tin and lead.