Question

Two point charges +3 µC and –3 µC are placed at a small distance 2 × 10 ^–3 m from each other. Find: 

(a) electric field and potential at a distance 0.6 m from dipole in its equatorial position.

(b) electric field and potential at the same distance from dipole as in (a) if the dipole is rotated through 90º.

Answer 1

Dipole moment

p = q × 2l = (3 × 10 –6 ) (2 × 10 ^–3 )

p = 6 × 10 ^–9 C-m

(a) Electric field in equatorial position,

Electric potential, V = 0

(b) On rotating the dipole through 90º, the same point now will be in axial position. So, electric field

and electric potential