A charge of #6# #C# passes through a circuit every #3# #s#. If the circuit can generate #24# #W# of power, what is the circuit's resistance?

1 Answer
Aug 6, 2016

Current is given by #I=Q/t#, so in this case is #I=6/3=2# #A#.

Power in an electric circuit is given by #P=I^2R#, which we can rearranged to make #R# the subject: #R=P/I^2=24/2^2=6# #Omega#.

Explanation:

Very briefly as an additional explanation, we often just remember Ohm's Law, #V=IR#, and #P=VI# for power, and substitute to find the expression we need. In this case, substituting in #IR# for #V# in the law for power gives us #P=IRxxI=I^2R#.