# A charge of 1 C passes through a circuit every 2 s. If the circuit can generate 7 W of power, what is the circuit's resistance?

Mar 14, 2018

$\text{28 Ω}$

#### Explanation:

Current in the circuit is

$i = \frac{Q}{t} = \text{1 C"/"2 s" = "0.5 A}$

Power ($P$), current ($i$) and resistance ($R$) are related as

$P = {i}^{2} R$

$R = \frac{P}{i} ^ 2 = \text{7 Watt"/("0.5 A")^2 = "28 Ω}$