A series circuit consists of a battery with internal resistance r and an external resistor R.If these two resistances are equal (r = R)then the energy dissipated per unit time by the internal resistance r is:
A)the same as by R
B)half that by R
C)twice that by R
D)one third that by R
E)unknown unless the emf is given

Question

Quizplus · Accepted Answer

In a series circuit, the current is the same through all components. When the internal resistance $r$ is equal to the external resistance $R$, the voltage drop across each will be the same (since $V = IR$), and thus the power dissipated (which is $P = I^2R$) will also be the same for both resistances.

A Series Circuit Consists of a Battery with Internal Resistance