Question

The resistance of the wire varies inversely as

• A. Area of cross-section
• B. Resitivity
• C. Length
• D. Temperature

Answer 1

The correct option is A

Area of cross-section

Explanation for the correct option:

1. Resistance is the property of a material by virtue of which it opposes the flow of electric current in it.
2. It is defined by $R=\frac{\rho l}{A}$, where $R$is the resistance, $\rho$ is the resistivity, $l$ is the length, and $A$is the area of the cross-section.
3. In case of option A, we can see from the above-explained expression that resistance is inversely proportional to the area of the cross-section of the wire.

Explanation for the incorrect options:

In case of option B, the resistance is directly proportional to the resistivity of the wire.

In case of option C, the resistance is directly proportional to the length of the wire.

In case of option D, the resistance is directly proportional to temperature.

Hence, option A is the correct answer.