Question

A battery having an emf of $12$ Volt and an internal resistance of $2\Omega$ is connected to another battery having an emf of $18$ Volt and an internal resistance of $2\Omega$ in such a way that they are opposing each other and the circuit is closed. Calculate the following.
$1$. Current flowing in the circuit.
$2$. Electrical power in the two batteries.
$3$.Terminal voltage of the two batteries.
$4$. Electric power consumed in the batteries.

Answer 1

$r_1=2ohm,r_2=2ohm$

$E_1=12V,E_2=18V$

$E_{net}=E_2-E_1=18-12=6V$

$r_{net}=r_1+r_2=4ohm$

$i=\frac{E_{net}}{r_{net}}=1.5A$

$V_{T_1}=18-\left(1.5\right)\left(2\right)=15V$

$V_{T_2}=12+\left(1.5\right)\left(2\right)=15V$

Power $=\frac{V^2}{R}$