Two concave lenses are kept in contact and magnitude of equivalent focal length is found to be `f_(1)`. Now the space between two lenses is filled with liquid of refractive index slightly more than 1. The magnitude of focal length of combination becomes `f_(2)`.

Options

A. `f_(1) = f_(2)`
B. ` f_(1)gt f_(2)`
C. ` f_(1)lt f_(2)`
D. ` f_(2)`cannot be defined

Answer

C

Explanation

Lens formed in between two concave lenses is convex one and hence overall focal length of combination increases.