$A$ car battery of $e.m.f.$ $12\,V$ and internal resistance $5 \times 10^{-2}\,\Omega$,receives a current of $60\,A$ from an external source. What is the terminal voltage of the battery (in $,V$)?

The internal resistance of a cell depends on

$A$ cell of internal resistance $r$ is connected to an external resistance $R$. The current will be maximum in $R$,if

Two identical cells each of emf $1.5 \,V$ are connected in parallel across an external resistance formed by two $20 \,\Omega$ resistors connected in parallel. $A$ voltmeter connected in the circuit measures $1.2 \,V$. The internal resistance of each cell is ................. $\Omega$.

Two sources of equal $emf$ $E$ are connected in series with an external resistance $R$. The internal resistances of the two sources are $R_1$ and $R_2$ $(R_2 > R_1)$. If the potential difference across the source of internal resistance $R_2$ is zero,then the value of $R$ is:

Four identical cells,each having an electromotive force $(e.m.f.)$ of $12\,V$,are connected in parallel. The resultant electromotive force $(e.m.f.)$ of the combination is .............. $V$.