# A charge of 40 C passes through a circuit every 8 s. If the circuit can generate 12 W of power, what is the circuit's resistance?

Jul 19, 2016

I found: $0.48 \Omega$

#### Explanation:

You can use your data to evaluate current as the rate of flow of charge in time to get:
$I = \frac{Q}{t} = \frac{40}{8} = 5 A$
We the use the definition of electrical power $P = V \cdot I$ and Ohm's Law, $V = R \cdot I$, to get:
$P = {I}^{2} \cdot R$
And
$12 = {5}^{2} \cdot R$
$R = \frac{12}{25} = 0.48 \Omega$