Assertion : If work done by the force depends on path then force is said to be conservative.
Reason : All the conservative forces are central force.

Assertion: Frictional forces are conservative forces.

Reason: Potential energy can be associated with frictional forces.

Assertion: When a force of $20 \mathrm{N}$ displaces a body by $5 \mathrm{m}$, then work done by this force must be $100 \mathrm{J}$ for every observer watching that body.

Reason: Work done on a body does not depend on the observer that is observing the body.

Assertion: When spring is elongated work done by spring is negative but when it is compressed work done by spring is positive.

Reason: Work done by spring is path-dependent.

Assertion: Work done by force of friction in moving a body in any round trip is zero.

Reason: Frictional force is a conservative force.