The terminal potential difference of a cell is greater than its $e.m.f.$ when it is

Two cells $P$ and $Q$ each of emf $2.16 \text{ V}$ are connected in series with a resistor of $19.6 \text{ } \Omega$. An ideal voltmeter reads $2 \text{ V}$ when connected across the cell $P$ and $1.92 \text{ V}$ when connected across the cell $Q$. The ratio of the internal resistances of the cell $P$ and $Q$ is

To get the maximum current from a parallel combination of $n$ identical cells,each of internal resistance $r$,connected to an external resistance $R$,which of the following conditions must be satisfied?

$A$ large number of cells, each marked $(6 \,V, 0.5 \,\Omega)$, are available to supply current to a device of resistance $0.75 \,\Omega$, which requires a current of $24 \,A$. How should the cells be arranged to transmit power to the load using the minimum number of cells?

The current provided by a battery is maximum when:

Two cells are connected between points $A$ and $B$ as shown. Cell $1$ has an emf of $12 \, V$ and an internal resistance of $3 \, \Omega$. Cell $2$ has an emf of $6 \, V$ and an internal resistance of $6 \, \Omega$. An external resistor $R$ of $4 \, \Omega$ is connected across $A$ and $B$. The current flowing through $R$ will be $............. \, A$.