Question

An electric dipole is free to move in a uniform electric field. Explain its motion when it is placed

i.) parallel to the field

ii.) perpendicular to the field.

Answer 1

1. When Dipole is placed parallel to the field

Ѳ = 0⁰, Sin Ѳ = 0⁰,so Ï„ = 0, hence dipole remains at rest.

2 When Dipole is perpendicular to the field

Ѳ = 90⁰, Ï„ = PESin90⁰ = PE, hence due to inertia the dipole will start executing oscillatory motion.