Q5
Electromotive Force
A battery has an emf of $$15.0 \,V$$. The terminal voltage of the battery is $$11.6 \,V$$ when it is delivering $$20.0 \,W$$ of power to an external load resistor $$R$$.
(a) What is the value of $$R$$?
(b) What is the internal resistance of the battery?