Question

Valerie’s 180 W electric rollers are plugged into a 150 V line in her bedroom. What is the resistance of the rollers when they are heated?

Answer 1

I = P /V

Where:

I = current

P = power = 180W

V = voltage = 150 V

I = 180W/150V = 1.2 A

Then, calculate:

R = V/I

R = resistance

R = 150V/1.2A = 125 ohms