Question

When the resistivity of all pure metals increases, then the temperature will:
A. decrease
B. increase
C. remains constant
D. first decreases and then increases

Answer 1

Resistance is the opposition to the flow of charges in a circuit. It depends on the length, area of cross section, resistivity and the temperature of the conductor. It is a fundamental property of the material.

Complete step by step answer:
Electrical resistance is the opposition to the flow of current in the conductor. It is the reciprocal of electrical conductance. We know that the resistance of the conductor depends on the material used, size and shape of the material, temperature of the material.
Thus that the resistance of the conductor depends on the material used, length of the material and area of material used .i.e.$R=\rho\dfrac{L}{A}$ where $\rho$ is the specific resistance or the resistivity, $L$ is the length of the resistance in meters and $A$ is the area of the resistance in square meters.
The resistance also depends on the temperature of the conductor, when the temperature rises the number of photons in the conductor increases, and hence the collision between electrons and photons.
Clearly, resistivity is a fundamental property of the material, and is dependent on the nature of the material and temperature. It is independent of the dimensions of the conductor.
Then if the resistivity of the conductor increases, then the temperature of the conductor will also increase.

So, the correct answer is “Option B”.

Note: Resistivity is a fundamental property of the material and is independent of the dimensions of the conductor. Whereas, resistance of a material depends on both the nature and the dimensions of the material. Also, resistivity is a special case of the resistance.