Question

A charge of `12 C` passes through a circuit every `3 s`. If the circuit can generate `8 W` of power, what is the circuit's resistance?

Answer 1

The resistance is `=2Omega`

Explanation:

We apply the following equation :

`P=RI^2`

Power, `P=8 W`

Current `=I`

Resistance `=R`

The current is related to the charge

`Q=It`

Charge, `Q=12C`

Time, `t=3s`

Current, `I=Q/t=12/3=4A`

Therefore,

The resistance is

`R=P/I^2=8/4^2=2 Omega`