Force of Gravity (ie., the Gravitational Force of Earth), Spring Force etc. are conservative forces; and we can define potential energy for any system with a conservative force. ex- Earth and ball system, spring and block system, etc.

We know that gravitational force exists between any two objects around us, though very negligible. Is this gravitational force also a conservative force? If so, can we define potential energy for a system of any two objects as ' the negative of work done on the other object by a conservative force'?

hello smriti,

you are right here. gravitational force is a conservative force. A conservative force is the force with the property that the work done in moving a particle between two points is independent of the path taken or the work done in a closed path is zero.

If you refer the NCERT textbook for class XI chapter Work, Energy and Power , you have the proof there showing Gravitational energy is conservative.

And potential energy for a system of  two objects is defined by many experienced physics teachers as the work done on one of the objects by all the conservative forces acting on the system.

Hope you understood what i said,

see ya