Question

Two electric dipoles each of
dipolemoment P = 6.2 x 10°C - m are
placed with their axis along the same line
and their centres at a distanced=10cm.
The force of attraction between dipoles
is​

Answer 1

Answer:

Correct option is

D

2.1×10−8N

Electric field due to a dipole on its axis is given by 2p/(4πϵ0r3)

Therefore using necessary approximation and F=qE we get,

F=2qp/(4πϵ0)(1/(d−l)3−1/(d+l)3)=2qp/(4πϵ0)6d2l/d6=6p2/4πϵ0d4

putting in the values,

F=6×9×109×6.22×10−60×1040=2.1×10−8N