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). The angular momentum of the charge q is constant. The linear momentum of the charge q is constant. The angular velocity of the charge q is constant. The linear speed of the charge q is constant.

The angular momentum is conserved because the electrostatic force is passing through the axis and hence the torque is zero (because the moment arm is 0 or we can say inr×F=0, as R is 0). If the torque is zero then angular momentum is conserved for -q (dL/dt=τ). Linear momentum is not conserved for -q because velocity is constantly changing its direction. As the distance of the object from the axis is changing (elliptical orbit), so angular velocity keeps changing in such a way to make angular momentum constant. Hence it is not conserved. The linear speed of the charge q is not constant because it is changing in such a way to make angular momentum constant.