Question

Two parallel rays are incident on a thin lens of refractive index 1.5 as shown in figure and radius of curvature of its surfaces are 30 cm & 60 cm . Origin of coordinate axes is at the optical centre of the lens.Then

75355
expand
This question has multiple correct options
A

focal length of lens is 120 cm

B

light rays get reflected (TIR) from first surface of the lens

C

y-coordinate of the point at which light rays focus is -4 cm

D

y-coordinate of the point at which light rays focus is 4 cm

Hard
Updated on : 2022-09-05
Solution
verified
Verified by Toppr
Correct options are A) and C)

We use the lens maker's formula, 



Since, a lens converges a parallel beam of light on its focus, the y coordinate of the lens is,


Thus,

Solve any question of Ray Optics and Optical Instrument with:-
Was this answer helpful?
upvote 0
downvote0
Similar questionsstar-struck