A positive point charge +Q is fixed in space. A negative point charge -q of mass m revolves around a fixed charge in elliptical orbit. The fixed charge +Q is at one focus of the ellipse. The only force acting on negative charge is the electrostatic force due to positive charge. Then which of the following satement is true.
Angular momentum of negative point charge about fixed positive charge is conserved
This is similar to a planet revolving around it's star. It's not in uniform circular motion. So its magnitude of velocity and hence linear momentum and KE keep changing. Only angular momentum X & total energy are conserved but not kinetic energy