What is surface density of charge ? How does it depend on the shape of the surface?

Define dielectric constant. What do you mean by the statement - dielectric constant of mica is $6$?

The mutual force of repulsion between two point charge having fixed distance between them is $9$ Dyne in vacuum and $4$ Dyne in a dielectric medium. What is the dielectric constant of the medium.

An electric dipole is held in a uniform electric field . By using suitable diagram, show that it does not undergo any translatory motion.

An electric dipole is held in a uniform electric field. Derive an expression for the torque acting on it and specify its direction.

Define the term 'electric dipole moment'. Give its unit.

Derive an expression for the maximum torque acting on an electric dipole when held in a uniform electric field.