Two small identical electrical dipoles AB and CD, each of dipole moment 'p' are kept at an angle of 120^o as shown in the figure. What is the resultant dipole moment of this combination? If this system is subjected to electric field ( $straight E with rightwards harpoon with barb upwards on top$ ) directed along + X direction, what will be the magnitude and direction of the torque acting on this?

Solution

Given, AB and CD are dipoles kept at an angle of 120^o to each other.

Resultant magnetic dipole moment is given by,
$Error converting from MathML to accessible text.$

Resultant magnetic dipole makes an angle 60^o with Y-axis or 30^o with x-axis.
Now, torque is given by,
$tau space equals p with rightwards harpoon with barb upwards on top space cross times space E with rightwards harpoon with barb upwards on top italic space italic space equals space p E space sin theta italic space italic space equals p E sin 30 to the power of o space space equals space 1 half pE space$

Direction of torque is along negative Z-direction.

For Daily Free Study Material Join wiredfaculty

Electric Charges And Fields

Some More Questions From Electric Charges and Fields Chapter

a) An electrostatic field line is a continuous curve. That is, a field line cannot have sudden breaks. Why not?
b) Explain why two field lines never cross each other at any point?

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation

Phone Number

Email Address

Loaction