Question

A charge of `36 C` passes through a circuit every `6 s`. If the circuit can generate `6 W` of power, what is the circuit's resistance?

Answer 1

`R = (6W)/(6A)^2= (6W)/(36A) = 1/6text( Ohms) ~= 0.17 Omega`
The circuit's resistance is around 0.17 Ohms.

Explanation:

The current, I, is equal to the charge passing through a point, every second.

I = dq / ds = 36C / 6 s = 6 C/s = 6 Amperes.

Now use, Power = P = `I^2 R`, and rearrange to make the resistance, R, the subject:

`R = P/I^2`
Enter known values for P and I.

`R = (6W)/(6A)^2= (6W)/(36A) = 1/6text( Ohms) ~= 0.17 Omega`