If a current of 3 A passing through a circuit generates 27 W of power, what is the resistance of the circuit?

$\implies R = \frac{P}{{I}^{2}} = \frac{27}{3} ^ 2 = 3 \Omega$
Power, $\left(P = {I}^{2} \cdot R\right)$
$\implies R = \frac{P}{{I}^{2}} = \frac{27}{3} ^ 2 = 3 \Omega$