Consider an electric dipole with moment of inertia I, consisting of point charges +q and -q which are separated by a fixed distance d.

(a) Determine the net force and net torque on the dipole in a uniform electric field E as a function of the angle Φ between dipole moment vector and the direction of the field. Include a clear figure with relevant items labeled.

(b) Now suppose that the dipole is released from rest close to its equilibrium orientation. What is the effective torsion constant, k, for this system?

(c) Calculate the frequency ω of small oscillations about the equilib-rium orientation.

(d) Now the dipole is brought into the field of a fixed point charge Q. which is at distance r from +q and distance (r + d) from q. We observe that the dipole accelerates towards Q. Is Q positive or negative?

(e) If the dipole has mass m, what will be the initial acceleration of the dipole in case (d)?