Question

Assertion$\left( A \right)$: At high temperatures, metal wires have a greater chance of short circuiting.
Reason$\left( R \right)$: Both resistance and resistivity of a material vary with temperature.
Is the reason the correct explanation of assertion?

Answer 1

In order to solve the question, we need to first mention the assertion and the reason that have been given. After that, it is mentioned whether the reason is the correct explanation for the assertion and after that the answer given is explained based on the behavior of metals on heating.

Complete step-by-step answer:
It is given in the assertion that at high temperatures, metal wires have a greater chance of short circuiting.
The reason for this statement in here is Both resistance and resistivity of a material vary with temperature.
We can see here that both the statements are correct but the reason is not the correct explanation of the assertion.
This can be explained in the following way:
At high temperatures, metal wires have a greater chance of short circuiting because the movement of electrons increases when the temperature is greater. The rise in flow causes further heat dissipation that melts the insulation of wires and can cause the short circuit in the cable. Also, both the resistance and the resistivity of the metal wire vary with temperature. Resistance is that property of a substance by virtue of which it opposes the flow of current through it. The resistance of a conductor is directly proportional to the temperature. While resistivity is an intrinsic property, it does not depend on size and shape but does depend on the temperature for the case of the metals as it increases with increase in temperature.

Note: It is important to note that justifying the correctness of both the statements does not mean that the reason that has been given is the correct explanation of the assertion given too. We need to correctly justify the cause of the reason being the explanation for the assertion to give a correct solution.