# A charge of 30 C passes through a circuit every 5 s. If the circuit can generate 42 W of power, what is the circuit's resistance?

May 25, 2016

$R = 1.17 \text{ } \Omega$

#### Explanation:

$I = \frac{\Delta Q}{\Delta t} \text{ The electric current passing through circuit}$

$\Delta Q = 30 C$
$\Delta t = 5 s$

$I = \frac{30}{5} = 6 A$

$P = {I}^{2} \cdot R$

$\text{P:Power}$
$\text{R:resistance}$

$42 = {6}^{2} \cdot R$

$42 = 36 \cdot R$

$R = \frac{42}{36}$

$R = 1.17 \text{ } \Omega$