# A charge of 40 C passes through a circuit every 8 s. If the circuit can generate 45 W of power, what is the circuit's resistance?

Apr 6, 2016

I found $1.8 \Omega$

#### Explanation:

We can get the current $I$ considering that:
$I = \frac{q}{t} = \frac{40}{8} = 5 A$
Now we use the power $P$ to write its expression involving current and resistance as:
$P = {I}^{2} R$
$R = \frac{P}{I} ^ 2 = \frac{45}{5} ^ 2 = \frac{45}{25} = 1.8 \Omega$