Will there be any effect on potential at a point if the medium around this point is changed?

Derive an expression for potential at a point due to a group of point charges?

Electric potential at a point in an electric field.

Derive an expression for electric potential at a point due to a point charge.

Define electric potential at a point. Derive an expression for the potential at a point due to a point charge.

Deduce an expression for potential at a point due to gravitational field.

Potentail at any point inside a charged hollow sphere

Show mathematically that the potential at a point on the equitorial line of an electic dipole is zero.