Question

Is it possible for two lenses in contact to produce zero power?

Answer 1

Answer:

Yes.

Explanation:

The power of some lens is given as the reciprocal of the focal length of the lens.

It is measured in units of Dioptre.

The focal length of a lens is that distance from the lens on its axis where the light rays from infinity converge or appear to converge.

The power of the combination of two lenses is given by the sum of the individual powers of the lenses.

Thus, if one lens is converging lens with some focal length so that its power is $\rm P_1 =P$ and the other lens diverging lens with the same focal length but with a negative sign so that its power is$\rm P_2 = -P.$, then the combination of these two lenses will be zero.

$\rm P_{total} = P_1+P_2 =P+(-P)=0.$