Question

A planet is revolving round the sun in an elliptical orbit. The work done on the planet by the gravitational force of sun is zero

• A. in some parts of the orbit
• B. in any parts of the orbit
• C. in no parts of the orbit
• D. in one complete revolution

Answer 1

Answer: (D)

in one complete revolution

As gravitational force is a conservative force and work-done by the conservative force over a closed loop is zero. Thus work-done by gravitational force is zero in a complete revolution.