Q.

Two thin lenses are of same focal lengths (f) but one is convex and the other one is concave. When they are placed in contact with each other, the equivalent focal length of the combination will be:

see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!
An Intiative by Sri Chaitanya

a

Infinite

b

f/4

c

Zero

d

f / 2

answer is A.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

detailed_solution_thumbnail

The focal length of the combination is given
by
1fcombination =1fconcave +1fconvex 1fcombination =1f+1f=0fcombination =

Watch 3-min video & get full concept clarity
score_test_img

Get Expert Academic Guidance – Connect with a Counselor Today!

whats app icon
Two thin lenses are of same focal lengths (f) but one is convex and the other one is concave. When they are placed in contact with each other, the equivalent focal length of the combination will be: