Expression for torque and potential energy stored in dipole placed in uniform electric field
Before the study of this topic students must have to know about electric field and electric dipole ;
In this topic we will discuss about the , Expression for torque and potential energy stored in dipole placed in uniform electric field . and what will be Expression for torque and potential energy stored in dipole placed in non-uniform electric field ?
Suppose an electric dipole AB having charges -q and +q are placed at distance 2a , and dipole moment ‘p’ is placed in an uniform electric field ‘E’ .
Then Electrostatic force experienced on both the charges are F = q E , but the direction of forces on each charges are opposite to each other . since the electric field E is constant then net force on the dipole will be zero ( since forces are in opposite directions ) .
Since the forces are equal , unlike and parallel acting at different points so , they form a couple . The couple tends to align the dipole axis along the direction of field ‘E’ .
Let’s draw AC perpendicular on electric field ‘E’ .
But Questions may be asked by the students that ,what will happen if electric field is not uniform ?
then its answer will be that the net force on the dipole will not be zero (0) . It means there will be translational and rotational motion in the dipole . And net force will be equal to F1-F2 .
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