In a certain region of space, there exists a uniform electric field of value $2\times10^2\hat k\, Vm^{-1}$. A rectangular coil of dimension $10\, cm\times20\, cm$ is placed in the $xy$ plane. The electric flux through the coil is......$Vm$

Three charges $2q,\, - q,\, - q$ are located at the vertices of an equilateral triangle. At the centre of the triangle

Find capacitance across $AB$

A thin metallic disc is rotating with constant angular velocity about a vertical axis that is perpendicular to its plane and passes through its centre. The rotation causes the free electrons in the disc to redistribute. Assume that, there is no external electric or magnetic field. Then,

If the distance between the plates of a capacitor having capacity $C$ and charge $Q$ is doubled then work done will be

A solid coducting sphere having a charge $Q$ is surrounded by an uncharged concentric  conducting hollow spherical shell. Let the potential difference between the surface of the  solid sphere and that of the outer surface of the hollow shell be $V$. If the shell is now  given a charge $-3Q$, the new potential difference between the same two surface is :-........$V$