An electric dipole of dipole moment magnitude p is placed in a uniform electric field of magnitude E, making an angle θ with the field direction.
a. (i) Write the expression for its potential energy and explain the physical meaning of each term.
b. (ii) For which values of θ is the potential energy maximum, minimum, or zero? Justify your answer without using calculus.
c. (iii) Discuss whether the orientations corresponding to maximum and minimum potential energy represent stable or unstable equilibrium, giving reasons.