In Fig., there are two convex lenses `L_(1)` and `L_(2)` having focal lengths `F_(1)` and `F_(2)` respectively. The distance between `L_(1)` and `L_(2)` will be :

Options

A. `F_(1)`
B. `F_(2)`
C. `F_(1) + F_(2)`
D. `F_(1) - F_(2)`

Answer

C

Explanation

`L_(1)` will converge the parallel ray at its focus. `L_(2)` will reder it parallel only when the refracted ray starts from the focus of `L_(2)`
`:.` Distance between `L_(1) L_(2) = F_(1) + F_(2)`