A dipole of moment `vecp` is placed in a uniform electric field `vecE`. The force on the dipole is `vecF` and the torque is `vec(tau)`

Options

A. (i), (ii) and (iii) are correct
B. (i) and (ii) are correct and (ii) is wrong
C. only (i) is correct
D. (i) and (ii) are correct and (iii) is wrong

Answer

B

Explanation

In a uniform electric field `vecE`, dipole experiences a torque `vec tau` given by `vec tau = vecp xx vecE` but expreiences no forces. The potenial energy of the dipole in a uniform electric field ` vecE` is `U = - vecp .vecE` .