Question

What is the resistance of a 2-kilometer long copper wire with a radius of 2 mm?

A) 0.001 ohms
B) 0.01 ohms
C) 0.1 ohms
D) 1 ohm

Answer 1

The resistance of the copper wire is 2 ohms.

Step-by-step explanation:

To calculate the resistance of a wire, we can use the formula:

Resistance = (resistivity * length) / (cross-sectional area)

First, we need to find the resistivity of copper. The resistivity of copper is approximately 1.7 x 10^-8 ohm-meter.

Next, we convert the length of the wire from kilometers to meters: 2 kilometers = 2000 meters.

We also need to convert the radius from millimeters to meters: 2 mm = 0.002 meters.

Now we can calculate the resistance: Resistance = (1.7 x 10^-8 * 2000) / (pi * (0.002)^2) = 2 ohms.

Therefore, the resistance of a 2-kilometer long copper wire with a radius of 2 mm is 2 ohms.