# A charge of 35 C passes through a circuit every 5 s. If the circuit can generate 42 W of power, what is the circuit's resistance?

Dec 10, 2016

$R \approx 0.857 \text{ } \Omega$

#### Explanation:

The unit of current, the Ampere, is defined as 1 Coulomb of charge per second, therefore, the current, $I$, in the given circuit is:

$I = \left(35 \text{ "C)/(5" S}\right) = 7 A$

One of the ways to compute power consumed by a circuit is, using the equation:

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

where I is the current and R is the resistance.

I will assume that you mean that the circuit consumes 42 Watts:

$42 W = {\left(7 A\right)}^{2} R$

Solve for R:

$R \approx 0.857 \text{ } \Omega$