A long cylinder has a charge density which is proportional to the distance from the axis: ρ = αr (for some constant α). The expression for the electric field inside this cylinder at a distance r is:

In a uniform electric field, an electric dipole experiences: (a) no net force (b) a non-zero torque (in general) Choose the correct option:

The electrostatic force of repulsion between two positively charged ions of equal charge is 3.7 × 10-9 N when the distance between them is 5 Å. The number of electrons missing from each ion is: