For the given circuit,find the potential at point $a$. (in $V$)

$27$ identical drops of mercury are charged simultaneously with the same potential of $10 \ V$. Assuming the drops to be spherical,if all the charged drops are made to combine to form one large drop,then its potential will be . . . . . . volt.

What is the effective capacitance between points $X$ and $Y$ in the given circuit? (All capacitors are in $\mu F$)

The charge on the $4 \mu F$ capacitor in the given circuit is (in $\mu C$)

$A$ proton and a deuteron are initially at rest and are accelerated through the same potential difference. Which of the following is false concerning the final properties of the two particles?

Two capacitors $C_1 = 2 \mu F$ and $C_2 = 4 \mu F$ are connected in a circuit as shown in the figure. The potential difference $(V_A - V_B)$ is....$V$