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

Two identical bulbs are connected in parallel across an ideal source of emf $E$. The ammeter $A$ and voltmeter $V$ are ideal. If bulb $B_2$ gets fused,then

The unit of $e.m.f.$ is

In the given circuit,the current flowing through the circuit is: (in $A$)

In the circuit shown below,the resistances are given in $\Omega$ and the battery is assumed ideal with an emf equal to $3\,V$. The voltage across the resistance $R_4$ is ................. $V$.

The galvanometer deflection,when key $K_1$ is closed but $K_2$ is open,equals $\theta_0$ (see figure). On closing $K_2$ also and adjusting $R_2$ to $5\,\Omega$,the deflection in the galvanometer becomes $\frac{\theta_0}{5}$. The resistance of the galvanometer is,then,given by [Neglect the internal resistance of battery]: .................. $\Omega$