A voltage of 40V is applied to the ends of a nichrome wire with a cross section of 0.5 mm2

A voltage of 40V is applied to the ends of a nichrome wire with a cross section of 0.5 mm2 and a length of 6 m. Determine the amperage in the wire.

Given:

S = 0.5 square millimeters – cross-sectional area of nichrome wire;

l = 6 meters – length of nichrome wire;

k = 1.4 Ohm * mm2 / m – resistivity of nichrome;

U = 40 Volts – electrical circuit voltage.

It is required to determine the current strength I (Ampere) in the wire.

Let’s find the total resistance of nichrome wire:

R = k * l / S = 1.4 * 6 / 0.5 = 8.4 / 0.5 = 16.8 ohms.

Then the current strength will be equal to:

I = U / R = 40 / 16.8 = 2.4 Amperes.

Answer: The current in the nichrome wire is 2.4 Amperes.