When a conductor with a diameter of 0.5 mm and a length of 4.5 m was included in the electric circuit

When a conductor with a diameter of 0.5 mm and a length of 4.5 m was included in the electric circuit, the potential difference at its ends turned out to be 1.2 V at a current of 1.0 A. What is the resistivity of the conductor material?

Given:

d = 0.5 mm – conductor diameter;

l = 4.5 meters – conductor length;

U = 1.2 Volts – potential difference at the ends of the conductor;

I = 1 Ampere – current strength.

It is required to determine p (Ohm * mm ^ 2 / m) – the resistivity of the conductor material.

Let’s find the total resistance of the conductor:

R = U / I = 1.2 / 1 = 1.2 Ohm.

Find the cross-sectional area of the conductor:

S = 3.14 * d ^ 2/4 = 3.14 * 0.5 ^ 2/4 = 0.2 mm ^ 2.

Then the resistivity of the conductor will be equal to:

p = R * S / l = 1.2 * 0.2 / 4.5 = 0.05 Ohm * mm ^ 2 / m.

Answer: the resistivity of the conductor is 0.05 Ohm * mm ^ 2 / m.