question_answer

In the case of dipole subjected to external electric field that gains torque, which of the following angle represents an unstable equilibrium:

A)                                                                               \[0{}^\circ\]

B)                                                                              \[45{}^\circ\]     

C)                                                                              \[90{}^\circ\]                        

D)                                                                              \[180{}^\circ\]