# A charge of 36 C passes through a circuit every 4 s. If the circuit can generate 72 W of power, what is the circuit's resistance?

Jan 17, 2017

The resistance is $R = 8 \Omega$

#### Explanation:

If a charge $36 C$ passes every $4$ seconds then the current is

## $I = \frac{Q}{t} = \frac{36}{4} = 9 A$

From the known power we can calculate the voltage:

## $U = \frac{72}{9} = 8 V$

Now we can calculate the resistance: