The charge accumulated on the capacitor connected in the following circuit is . . . . . . $\mu C$ (Given $C=150\ \mu F$)

Potential difference between $A$ and $B$ is .............. $V$.

What are the advantages of the null-point method in a Wheatstone bridge? What additional measurements would be required to calculate $R_{\text{unknown}}$ by any other method?

$ABCD$ is a square where each side is a uniform wire of resistance $1\,\Omega$. $A$ point $E$ lies on $CD$ such that if a uniform wire of resistance $1\,\Omega$ is connected across $AE$ and a constant potential difference is applied across $A$ and $C$,then $B$ and $E$ are equipotential.

The electric current $i$ in the circuit shown is (in $\text{ A}$)

In the Wheatstone's bridge (shown in figure) $X = Y$ and $A > B$. The direction of the current between $a$ and $b$ will be