Question

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?

Answer 1

`R ~~ 0.857" "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 = (35" "C)/(5" S") = 7 A`

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

`P = I^2R`

where I is the current and R is the resistance.

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

`42 W = (7 A)^2R`

Solve for R:

`R ~~ 0.857" "Omega`