$A$ battery of internal resistance $4 \,\Omega$ is connected to the network of resistances as shown. In order to give the maximum power to the network,the value of $R$ (in $\Omega$) should be

In the circuit shown,the energy stored in the capacitor is $n\,\mu J$. The value of $n$ is ..............

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]: .................. $\Omega$

Considering the following circuit,select the correct alternative.

For the circuits $A$ and $B$ as shown in the figure,identify the correct option.

$A$ current of $1.5\, A$ flows through a copper voltameter. The thickness of copper deposited on the electrode surface of area $50\, cm^2$ in $20\, min$ will be (Density of copper $= 9000\, kg/m^3$ and $E.C.E.$ of copper $= 0.00033\, g/C$).