How much power is produced if a voltage of #9 V# is applied to a circuit with a resistance of #12 Omega#?

1 Answer
Jan 10, 2016

#6.75W#

Explanation:

Power in electric circuits may be given by any of the following 3 equations :

#P=VI=I^2R=V^2/R#.

They may all be derived from definitions, together with Ohms' Law.
(Ask me if you want me to show you how to derive them as well).

In this case, we use the latter equation since that is what information is given in the question.
Doing so we obtain

#P=V^2/R=9^2/12=6.75W#.