A convex lens is dipped in a liquid, whose refractive index is equal to the refractive index of the lens. Then, its focal length will

Options

A. become zero
B. becomes infinite
C. remain unchanged
D. become small, but non - zero

Answer

B, C

Explanation

`(1)/(f_(1))=((mu_(g))/(mu_(e))-1)((1)/(R_(1))-(1)/(R_(2)))=(1-1)((1)/(R_(1))-(1)/(R_(2)))=0,f_(1)=oo`