In the circuit shown in the figure,the currents in different branches and the value of one resistor are given. Then,the potential at point $B$ with respect to point $A$ is $.......V$.

$A$ battery of $e.m.f.$ $10\, V$ and internal resistance $0.5\, \Omega$ is connected across a variable resistance $R$. The value of $R$ for which the power delivered in it is maximum is given by ......... $\Omega$.

Thirteen resistances,each of resistance $R \, \Omega$,are connected in the circuit as shown in the figure below. The effective resistance between $A$ and $B$ is

Find the current passing through the battery immediately after the key $(K)$ is closed. It is given that initially all the capacitors are uncharged. (Given that $E = 5 \, V$, $R = 6 \, \Omega$) (in $A$)

In the given circuit,an ideal voltmeter connected across the $10\,\Omega$ resistance reads $2\,V$. The internal resistance $r$ of each cell is ................... $\Omega$.

$A$ circuit is comprised of eight identical batteries and a resistor $R = 0.8\,\Omega$. Each battery has an $emf$ of $1.0\, V$ and internal resistance of $0.2\,\Omega$. The voltage difference across any of the batteries is ............. $V$.