Question

For a dipole with moment \[\vec{p}\] placed at angle θ to a uniform electric field \[\vec{E}\], what is the perpendicular distance from the center of the dipole to the line of action of force on either charge?

Options

• 2l sin θ

• l sin θ (for both charges)

• l sin θ

• l cos θ

Answer 1

When a dipole of separation 2l is inclined at angle θ to the electric field, the perpendicular distance from the dipole center to the line of action of force on the positive charge is l sin θ, and similarly for the negative charge it is also l sin θ. This perpendicular distance is crucial in calculating the torque using the moment arm.