Question

Draw the orientation of electric dipole moment in a uniform electric field such that the dipole experiences 1÷√2 times the maximum torque

Answer 1

Answer:

The force on charge +q = FA = qE along the direction of vector E

The force on charge –q = FB = qE opposite to the direction of vector E

As these two forces are equal, opposite and parallel so they form a couple

We know that Torque т = Force * Arm of the couple

T = Force X Arm of couple

= F X AB sin Ɵ

= qE X AB sin Ɵ

= qE X 2a sin Ɵ

= (q X 2a) E sin Ɵ

= pE sin Ɵ where p is the dipole moment

= vector p X vector E