Electric dipole

in electric field

 


 

1)Suppose a dipole is placed in an electric field with intensity E

2)dipole has charges  +q  and   -q  separated by a distance 2a


3)dipole making an angle with the electric field.


4)the force acting on +q is

= qE

5) the force acting on - q is

= - qE


6)As the two forces are equal and opposite, as shown in the diagram, but acting in different position of the same object. So a torque will generate.




7)the magnitude of torque is

 t = force × perpendicular distance between the two force

t = qE × XY




Where P = 2aq is the dipole moment of the dipole. The direction of this torque is perpendicular to the both P and E.