Twelve wires of equal length and equal cross-sectional area form a cube. If the resistance of each wire is $R$,then the effective resistance between the two ends of a diagonal is:

In the circuit shown below,the reading of the voltmeter $V$ is ........... (in $, V$)

$A$ battery of internal resistance $4\,\Omega$ is connected to a network of resistors as shown in the figure. If maximum power is to be delivered to the network,the magnitude of $R$ in $\Omega$ should be:

An infinite ladder network of resistors is shown in the figure. If $R_1 = 1 \, \Omega$ and $R_2 = 2 \, \Omega$,then the equivalent resistance between $A$ and $B$ is ................ $\Omega$.

The sliding contact $C$ is at one-fourth of the length of the potentiometer wire $(AB)$ from $A$ as shown in the circuit diagram. If the resistance of the wire $AB$ is $R_0$,then the potential drop $(V)$ across the resistor $R$ is

For a cell, the graph between the potential difference $(V)$ across the terminals of the cell and the current $(I)$ drawn from the cell is shown in the figure. The $e.m.f.$ and the internal resistance of the cell are