Question

A point dipole with dipole moment, \( \vec{p} = p_0 \hat{k} \), is kept at the origin. An external electric field given by, \( \vec{E} = E_0(2\hat{i} - 3\hat{j} + 4\hat{k}) \), is applied on it. Which one of the following statements is true?

• A. The force on the dipole is zero while torque rotates the dipole on the $xy$-plane
• B. The force on the dipole moves it along the direction of electric field
• C. The interaction energy between the dipole and electric field is zero
• D. The potential due to the dipole alone on the $xy$-plane with $z = 0$ depends on the value of $p_0$
• E. The application of the electric field orients the dipole along the $-\hat{k}$ direction

Hint:

In a uniform field, a dipole only experiences torque, not linear force. Also, for a dipole oriented along the $z$-axis, the $xy$-plane ($z=0$) is an equipotential surface with $V=0$ because the position vector is always perpendicular to the dipole moment.

Answer 1

The Correct Option is A