The potential difference in open circuit for a cell is $2.2\, V$. When a $4\, \Omega$ resistor is connected between its two electrodes,the potential difference becomes $2\, V$. The internal resistance of the cell will be .............. $\Omega$.

$A$ current of $2\,A$ is flowing through a cell of $e.m.f.$ $5\,V$ and internal resistance $0.5\,\Omega$ from negative to positive electrode. If the potential of the negative electrode is $10\,V$,the potential of the positive electrode will be .............. $V$.

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

There are a large number of cells available,each marked $(6 \,V, 0.5 \,\Omega)$,to be used to supply current to a device of resistance $0.75 \,\Omega$,requiring $24 \,A$ current. How should the cells be arranged so that power is transmitted to the load using the minimum number of cells?

$A$ battery of emf $18 \, V$ and internal resistance $3 \, \Omega$ and another battery of emf $10 \, V$ and internal resistance $1 \, \Omega$ are connected in parallel as shown in the figure. The voltmeter reading is: (in $ \, V$)

$EMF$ is most closely related to