The current in the arm $CD$ of the circuit will be

The equivalent resistance between points $A$ and $B$ is ............ $\Omega$.

In the circuit shown,$P \ne R$. The reading of the galvanometer is the same with switch $S$ open or closed. Then:

If in the experiment of Wheatstone's bridge,the positions of cells and galvanometer are interchanged,then the balance point will

In the circuit shown in the figure, all the resistances are identical and each has the value $r \ \Omega$. The equivalent resistance of the combination between the points $A$ and $B$ will remain unchanged even when the following pairs of points marked in the figure are connected through a resistance $R$.

Refer to the circuit diagram given below. The heat generated across the $6\text{ }\Omega$ resistance in $100\text{ s}$ is $\frac{\alpha}{100}\text{ J}$. The value of $\alpha$ is . . . . . . . (Nearest integer)