Question

Question #aaeaa

Answer 1

Positive power(`D`) of a lens means positive focal length(`f`),i.e lens is converging in nature.

They are related as, `D=100/f` (in cm)

So,the lens has a focal length of `100/1.5 =66.67 cm`

And,remember,lens with positive power is given to a patient of Hypermetropia where the eyeball has smaller dimensions than normal and as a result of this refractive error,image is formed behind the fovea.

So a converging lens is recommended, so that it can converge the light more to make the image fall on fovea within that shortened distance.

Answer 2

`0.67m` it's converging in nature.

Explanation:

`D=1/f`

`f=1/D`

`=1/1.5`

`=0.67m`

Converging lens always posseses positive power.