Assertion (A): A fuse wire must have a high resistance and a low melting point. Reason (R): This ensures it melts quickly and breaks the circuit when an excessively high current flows. MCQ with Answer and Explanation

Assertion (A): A fuse wire must have a high resistance and a low melting point. Reason (R): This ensures it melts quickly and breaks the circuit when an excessively high current flows.
A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is NOT the correct explanation of A.
C. A is true but R is false.
D. A is false but R is true.
Answer: Option A
Solution (By JKSSB Mock Tests)
A fuse is a safety device. It must have a relatively high resistance so that it produces heat quickly when a large current passes through (H = I²Rt). It must have a low melting point so that this heat causes it to melt immediately, breaking the circuit and protecting appliances. Thus, both A and R are true, and R explains A.

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