Question

Assertion: At high-temperature metal wire have a greater chance of short-circuiting

Reason: both resistance and resistivity vary with temperature.

Is the reason correct explanation of the assertion?

Answer 1

Explanation for Assertion statement

1. At high-temperature metal wire has a greater chance of short-circuiting this is correct.
2. At high temperatures, the flow of electrons will be increased in the conductor.
3. Due to high electron flow in the conductor, the heat dissipation will increase in the conductor as heat. This dissipation is due to the collision between mobile electrons and ions.
4. The dissipated heat will melt the insulation of the conducting wire and it will be short-circuited.

Explanation for Reason statement

1. The reason is correct but it is not the correct explanation of the assertion.
2. We know $R=\rho \frac{L}{A}$, where, R is the resistance, $\rho$ is the resistivity, and L and A are the lengths and cross-sectional area of the conductor. So resistance is proportional to the resistivity.
3. Again if the temperature increase due to the collision of electrons and ions the resistance will increase, i.e., resistivity will increase.

Therefore, assertion and reason both are correct, but the reason is not the correct explanation of assertion.