Question

An electric dipole with dipole moment `4xx10^(9)` Cm is aligned at `30^(@)` with the direction of a uniform electric field of magnetude `5xx10^(4)NC^(-1)`. Calculate the magnitude of the torque acting on the dipole.

Answer 1

Given, `P=4xx10^(-9) C-m, E=5xx10^(4)N//C, theta=30^(@)`
Torque, `tau = PE sin theta`
`=4xx10^(-9) xx5xx10^(4) sin 30^(@)=(20xx10^(-5))/2=10^(-4) N-m`
The direction of torque is `bot^(r)` to both electric field and dipole moment.