A double convex lens of refractive index `m_(1)` is immersed in a liquid of refractive index `m_(2)`. This lens will act as:

Options

A. a convex lens
B. a concave lens
C. a glass plate
D. a convexo concave lens

Answer

C

Explanation

For first refraction surface.
For parallel beam of light, `(-mu_(1))/(u)+(mu_(2))/(V)=(mu_(2)-1)/(R )`
`rArr -(1.4)/(0oo)+(1.5)/(V)=(1.5-1.4)/(R )rArrV=15R`
For second refraction surface,
`-(mu_(2))/(1.5r)+(mu_(3))/(V)=(mu_(2))/®`
`rArr -(1.5)/(15R)+(1.6)/(V)=(1.6-1.5)/(R)rArrV'=oo`
Hence ,the combination behaves as glass plate