Question

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).

• 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 1

Answer: (A)

The angular momentum of the charge $- q$ is constant

Answer 2

Net torque on ( - q) about a point (say P) lying over + Q is zero. Therefore, angular momentum of ( - q ) about point P should remain constant.