Define power of a lens

Define power of lens and give its units.

Define 1 dioptre of power of a lens

Define 1 dioptre of power of a lens

Whether the power of a lens will be more in air or in water?

Explain whether power of a lens will be more in air of water?

Define the term 'resolving power of a telescope'. How will the resolving power be affected with the increase in Diameter of the objective lens? Justify your answer.

Define linear magnification produced by a lens.Hence derive expression for it also define the power of a lence and its unit.