Question

A resistor with a potential difference of 15.0 V develops a heat output of 327 W.

a) What is its resistance?
b) What is the current across the resistor?

Answer 1

V = I * R voltage drop

P = I * V = I^2 * R power

I = P / V = 327 / 15 = 21.8 amps

b) I = 21.8 amps

a) R = P / I^2 = 327 / 21.8^2 = .69 ohms

Check:

V = I R = 21.8 * .69 = 15 Volts