Question

A charge of `35 C` passes through a circuit every `5 s`. If the circuit can generate `82 W` of power, what is the circuit's resistance?

Answer 1

`1.67` ohms

Explanation:

We first find the current produced, which is given by the equation,

`I=Q/t`

where:

• `I` is the current in amperes

• `Q` is the charge in coulombs

• `t` is the time in seconds

So here, we get:

`I=(35 \ "C")/(5 \ "s")=7 \ "A"`

Then, power is given through the equation:

`P=I^2R \ (because V=IR \ "and" \ P=IV)`

where:

• `P` is the power in watts

• `R` is the resistance in ohms

So, we get:

`82 \ "W"=(7 \ "A")^2*R`

`R=(82 \ "W")/(49 \ "A"^2)`

`=1.67 \ Omega`