Calculate the resistance of a copper wire with a length of 50 m and a cross-sectional area of 1.4 mm2.

Given:

l = 50 meters – the length of the copper wire;

S = 1.4 mm2 – cross-sectional area of the copper wire;

k = 0.018 Ohm * mm2 / m – copper resistivity.

It is required to determine R (Ohm) – the resistance of the copper wire.

To determine the resistance of a copper wire, you need to use the following formula:

k = R * S / l, hence:

R = k * l / S = 0.018 * 50 / 1.4 = 0.9 / 1.4 = 0.64 Ohm.

Answer: the resistance of the copper wire is 0.64 ohms.