Question Detail

MTH 102 PHY 102 Past Questions Objective Question

Question

Which of the following copper conductors has the least resistance?
Options
A thin, long and hot
B thick, short and cool
Correct Answer
C thick, long and hot
D thin, short and cool
Correct Answer

Option B is the correct answer.

Detailed Explanation

The resistance (R) of a conductor is given by the formula R = ρL/A, where ρ is the resistivity, L is the length, and A is the cross-sectional area.To minimize resistance, we need:1. Shortest length (L): Shorter wires have less resistance.2. Largest cross-sectional area (A): Thicker wires have less resistance.3. Lowest resistivity (ρ): Resistivity of metals like copper increases with temperature, so a cooler wire has lower resistivity.Combining these factors, a conductor that is thick, short, and cool will have the least resistance.

Hint

Recall the factors affecting resistance: length, cross-sectional area, and resistivity. How does temperature affect resistivity?

Question Info