A planet is revolving around the sun as shown in elliptical path. The correct option is

Options

A. its total energy is negative at D.
B. its angular momentum is constant
C. net torque on planet about sun is zero.
D. linear momentum of the planet is conserved.

Answer

A, B, C

Explanation

For (A): for bounded system the total energy is always negative.
For (B): for centrel force field, angular momentum is always conserved
For (C): for central force field torque `=0`
for (D): in presence of external force, linear momentum is conserved.