Two point charges – 4 μc and 4 μc, constituting an electric dipole, are placed at (– 9, 0, 0) cm and (9, 0, 0) cm in a uniform electric field of strength 104 NC–1. The work done on the dipole in rotating it from the equilibrium through 180° is :
1
14.4 mJ
2
18.4 mJ
3
12.4 mJ
4
16.4 mJ