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Q10 (NDA-I/2011) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Electricity and magnetism Answer Verified

The material used for electric fuse is an alloy of tin and lead. This alloy should have:

Result
Your answer: —  Â·  Correct: A
Explanation

An electric fuse is a safety device designed to protect electrical circuits from overcurrent. The material used for a fuse, typically an alloy of tin and lead, must possess a low melting point and high specific resistance (resistivity). A low melting point ensures that the wire melts quickly when excessive current flows, thereby breaking the circuit and preventing damage [t1, t3, t6]. High specific resistance is crucial because the heat generated in a conductor is proportional to its resistance (H = I²Rt); thus, a material with high resistivity generates sufficient heat rapidly to reach its melting point during an overload or short circuit [t1, t2]. While some sources mention conductivity for normal operation [t4, t5], the defining safety characteristics for a fuse element to function as a circuit breaker are high resistivity and a low melting point [t1, t2].

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