To draw maximum current from a combination of cells,how should the cells be grouped?

The internal resistance of a cell is the resistance of

When two identical batteries of internal resistance $1 \Omega$ each are connected in series across a resistor $R$,the rate of heat produced in $R$ is $J_1$. When the same batteries are connected in parallel across $R$,the rate is $J_2$. If $J_1 = 2.25 J_2$,then the value of $R$ in $\Omega$ is

The potential difference across a cell and the current through it are shown in the graph. $A$ battery consists of $40$ such identical cells. The maximum current supplied by the battery through a load of $2.5\,\Omega$ is equal to .............. $A$.

Four identical cells, each of $2 \, V$ e.m.f., are connected in parallel. They supply current to an external circuit consisting of two $15 \, \Omega$ resistors connected in parallel. The terminal voltage of the equivalent cell, as measured by an ideal voltmeter, is $1.6 \, V$. Calculate the internal resistance of each cell in $\Omega$.

For a cell with non-zero (finite) internal resistance,write the relation between the terminal voltage $(V)$ and the electromotive force $(E)$ of the cell.