Consider an electric dipole whose dipole moment (a vector pointing from the negative charge to the positive charge) is oriented at an angle Ā with respect to the y-axis. There is an external electric field of magnitude EĀ (independent of the field produced by the dipole) pointing in the positive y-direction. The positive and negative ends of the dipole have charges +q and -q, respectively, and the two charges are a distance d apart. The dipole has a moment of inertia I about its center of mass. It will help you to imagine that the dipole is free to rotate about a pivot through its center.
A) What is the net force Ā Ā that the dipole experiences due to the electric field?
B) What is Ā , the magnitude of the torque that the electric field exerts about the center of mass of the dipole?
C) Using the above result, find the potential energy associated with the dipole's orientation in the field as a function of the angleĀ Ā Ā shown in the figure. Take the zero of the potential to occur when the dipole is at angle Ā ; that is Ā , .
D) In terms of the dipole moment Ā , What is the expression for the torque on a dipole in the field Ā ?
E) In terms of the dipole moment, What is the expression for the potential energy of a dipole in the field?
Ā
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