Home
Class 12
PHYSICS
A concave lens of glass, refractive inde...

A concave lens of glass, refractive index 1.5 has both surfaces of same radius of curvature R. On immersion in a medium of refractive index 1.75, it will behave as a

A

Convergent lens of focal length 3.5 R

B

Convergent lens of focal length 3.0 R

C

Divergent lens of focal length 3.5 R

D

Divergent lens of focal length 3.0

Text Solution

Verified by Experts

The correct Answer is:
A
Since,` (n)_("liquid") gt (n)_("lens")`
Hence concave lens will behave as convergent lens
`(f_(1))/( f_(a)) = ((n_(ga)- 1))/(( n_(gl)-1)) = (1.5 - 1)/((1.5)/(1.75)-1)`
`rArr f_(1) = - 3.5 f_(a)`
as `(1)/(f_(a)) = (1.5 -1) ((2)/(R))`
`f_(a) = R `
`:. f_(1) = - 3.5 R `
Promotional Banner

Similar Questions

Explore conceptually related problems

A convax lens of glass ,refractive index 1.5 ,has both surfaces of same radius of curvature R. On immersion in a medium of refractive index 1.75 ,it wuill behaves as a (A)convergent lens of focal length 3.5R (B)convergent lens of focal length 3.0R (C)divergent lens of focal length 3.5R (D)divergent lens of focal length 3.0R

A convex lens made up of glass of refractive index 1.5 is dippedin turn (i) in a medium of refractive index 1.65 (ii) in a medium of refractive index 1.33 (a) Will it behave as converging or diverging lens in the two cases ? (b) How will its focal length changes in the two media ?

A double convex lens of + 5 D is made of glass of refractive index 1.5 with both faces of equal radii of curvature. Find the value of curvature.

A diverging lens of refractive index 1.5 and focal length 15 cm in air has same radii of curvature for both sides. If it is immersed in a liquid of refractive index 1.7 , calculate focal length of the lens in liquid.

The adjacent figure shows a thin plano-convex lens of refractive index mu_1 and a thin plano-concave lens of refractive index mu_2 , both having same radius of curvature R of their curved surfaces. The thin lens of refractive index mu_3 has radius of curvature R of both its surfaces. This lens is so placed in between the plano-convex and plano-concave lenses that the plane surfaces are parallel to each other. The focal length of the combination is

A thin convex lens made of glass of refractive index 3//2 has a power of 5 D. When it is immersed in a liquid of refractive index mu , it behaves like a divergent lens of focal length 1 m. Calculate the refractive index of the liquid.

A thin glass (refractive index 1.5) lens has optical power of -5D in air. Its optical power in a liquid medium with refractive index 1.6 will be