Under the influence of the coulomb field of charge + Q, a charge - q is moving around it in an elliptical orbit. Find out the correct statement (s).

Options

A. The angular momentum of the charge - q is constant .
B. The linear momentum of the charge - q is constant .
C. The angular velocity of the charge - q is constant
D. The linear speed of the charge - q is constant .

Answer

A

Explanation

The sitution is shown in the figure which is similar to a planet revolving around sun . The distance of - q from + Q is changing , therefore force between the charges will change .
The speed of the charge - q will be greater when the charge is nearer to + Q as compared to when it is far . Therefore . the angular velocity of charge - q is also variable . The direction of the velocity changes continuously , therefore linear momentum is also variable . The angular momentum of (-q) about Q is constant because the torque about + Q is zero .