A charge of #25 C# passes through a circuit every #4 s#. If the circuit can generate #1 W# of power, what is the circuit's resistance?

1 Answer
May 28, 2017

The circuit resistance is #=25.6mOmega#

Explanation:

We apply the equation

#Q=It#

The charge is #Q=25C#

The time is #t=4s#

The current is #I=Q/t=25/4A#

The power

#P=UI#

But according to Ohm's Law

#U=RI#

So,

#P=RI*I=RI^2#

So,

the resistance is #R=P/I^2#

#=1/(25/4)^2=0.0256Omega#