In a certain region of space, electric field is along the z-direction throughout. The magnitude of electric field is, however not constant but increases uniformly along the positive z-direction at the rate of `10^(5)NC^(-1)m^(-1)`. What are the force and torque experienced by a system having a total dipole moment equal to `10^(-7)` Cm in the negative z-direction?

Explanation

Only (c ) is right the rest cannot represent electrostaic field lines (a) is wrong because field lines must be normal to a conlductor (b) is wrong because field lines cannot start wrong because electrostatic field lines cannot form closed loops