Condenser Ahas a capacity of $15\  \mu F$ when it is filled with a medium of dielectric constant $15$. Another condenser $B$ has a capacity $1\  \mu F$ with air between the plates. Both are charged separately by a battery of $100\,V$ . After charging, both are connected in parallel without the battery and the dielectric material being removed. The common potential now is…….$V$

In the circuit shown, a potential difference of $30\, V$ is applied across $AB$ . The potential difference between the points $M$ and $N$ is….$V$

A point charge $q$ is situated at a distance $d$ from one end of a thin non – conducting rod of length $L$ having a charge $Q$ (uniformly distributed along its length) as shown in fig.Then the magnitude of electric force between them is

Four capacitors with capacitances $C_1 = 1\,μF, C_2 = 1.5\, μF, C_3 = 2.5\, μF$ and $C_4 = 0.5\, μF$ are connected as shown and are connected to a $30\, volt$ source. The potential difference between points $B$ and $A$ is….$V$

Electrostatic field of a long uniformly charged wire varies with distance $(r)$ according to relation