Eight identical cells,each having an electromotive force $E$ and internal resistance $r$,are connected in series to form a closed circuit. An ideal voltmeter is connected across $2$ cells. The voltmeter will read ........ $E$.

$A$ cell $E_{1}$ of $emf 6 V$ and internal resistance $2 \Omega$ is connected with another cell $E_{2}$ of $emf 4 V$ and internal resistance $8 \Omega$ as shown in the figure. The potential difference across points $X$ and $Y$ is............ $V$.

Two batteries of emf $\varepsilon_1$ and $\varepsilon_2$ (where $\varepsilon_2 > \varepsilon_1$) and internal resistances $r_1$ and $r_2$ respectively are connected in parallel as shown.

Ten identical cells each emf $2 \, V$ and internal resistance $1 \, \Omega$ are connected in series with two cells wrongly connected. $A$ resistor of $10 \, \Omega$ is connected to the combination. What is the current through the resistor (in $ \, A$)?

When a current of $2 \ A$ flows through a resistor of $2 \ \Omega$,the terminal voltage across the cell is $E/2$. The internal resistance of the cell is ........ $\Omega$.

$A$ cell of $emf\;4\,V$ and internal resistance $0.5\,\Omega$ is connected to a $7.5\,\Omega$ external resistance. The terminal potential difference of the cell is $.....\,V$.