Question

Resistivity does not change if

• A. Material is changed.
• B. Temperature is changed.
• C. The shape of the resistor is changed.
• D. Both material and temperature are changed.

Answer 1

The correct option is C

The shape of the resistor is changed.

Resistivity: It is defined as the resistance present inside a material per unit length in a unit cross-sectional area. The resistivity of the material is its characteristic property and is different for different materials.

The diagram to represent resistivity:

The formula to calculate resistivity:

$\rho =\frac{Ra}{l}$

$R=$resistance

$a=$cross-section area

$l=$length

$\rho =$resistivity

Explanation of resistivity:

1. Resistivity depends on the nature of the material of the wire. So changing the shape of the resistor will not affect the resistivity of the material.
2. Resistivity depends upon the temperature, that is, it changes with the change in the temperature.
3. Thus, resistivity is dependent of the type of material, and temperature. but it is independent of the shape of the resistor.

Hence, option (C) is the correct answer.