(i) Examples of conservative forces are gravitational forces `,` electrostatic forces.
Examples of non- conservative forces are frictional forces `,` viscous forces.
(ii) Potential energy is the enrgy stored in the body on account of work done on teh body. Non conservative forces are only the opposing forces, you go one way or the other. Work done against them is a shear forces are only the opposing forces, you go one way or the other. Work done against them is a shear waste.It is not retrievable. ltbr. In day to day life, it implies that whatever way of life we adopt, there are hurdles, obstacles, loop holes which act as sinks of energy. They must be minimised to the extent possible. Energy spent againt them is not retrieveable.