Two equal $-ve$ charges $-q$ are fixed at the points $(0, a)$ and $(0, -a)$ on the $y-$ axis. A positive charge $Q$ is released from rest at the point $(2a, 0)$ on the $x-$ axis. The charge will

A parallel plate capacitor is charged to a potential difference of $100\ V$ and disconnected from the source of emf. A slab of dielectric is then inserted between the plates. Which of the following three quantities change?

$(i)$ The potential difference
$(ii)$ The capacitance
$(iii)$ The charge on the plates

A capacitor is charged by using a battery which is then disconnected. A dielectric slab is then slipped between the plates, which results in

Find the equivalent capacitance across $A$ $\&$ $B$ ........$\mu f$

Two identical point charges are placed at a separation of $ l.$ $P$ is a point on the line joining the charges, at a distance $x$ from any one charge. The field at $P$ is $E$. $E$ is plotted against $x$ for values of $x$ from close to zero to slightly less than $l$. Which of the following best represents the resulting curve?

A thin spherical conducting shell of radius $R$ has charge $q$. Another charge $Q$ is placed at the centre of the shell. The electrostatic potential at a point $P$ at a distance $R/2$ from the centre of the shell is