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# 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 $10^5\; NC^{−1}$ per metre. 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?

The force is $10^{–2}\; N$ in the negative z-direction, that is, in the direction of decreasing electric field. You can check that this is also the direction of decreasing potential energy of the dipole; torque is zero.