In the figure shown, the potential difference between points $A$ and $B$ is......$V$

The electric potential $V$ at any point $(x, y, z)$ (all in $metres$ ) in space is given by $V = 4x^2\, volt$. The electric field at the point $(1\, m, 0, 2\, m)$ in $volt/metre$ is

Four charges are placed at the circumference of a dial clock as shown in figure. If the clock has only hour hand, then the resultant force on a charge $q_0$ placed at the centre, points in the direction which shows the time as:

A parallel plate capacitor with air between the plates has a capacitance of $9\, pF$. The separation between its plates is $'d'$. The space between the plates is now filled with two dielectrics. One of the dielectrics has dielectric constant $K_1=3$ and thickness $\frac{d}{3}$ while the other one has dielectric constant $K_2 = 6$ and thickness $\frac{2d}{3}$ . Capacitance of the capacitor is now.........$pF$

Two identical charged spherical drops each of capacitance $C$ merge to form a single drop. The resultant capacitance

Two spherical conductors each of capacity $C$ are charged to potential $V$ and $-V$ . These are then connected by mean of a fine conducting wire. The loss of energy will be