A thin convex lens of focal length ‘f’ is put on a plane mirror as shown in the figure. When an object is kept at a distance ‘a’ from the lens - mirror combination, its
image is formed at a distance in front of the combination. The value of ‘a’ is :
As we learnt in
Thin lens formula -
- wherein
are object and image distance from lens.
When object is kept at distance a from thin convex lens.
By lens formula
(i)
Mirror forms image at equal distance from mirror
From lens formula
After solve we get
a = 2f
Correct option is 2.
Option 1)
This is an incorrect option.
Option 2)
This is the correct option.
Option 3)
This is an incorrect option.
Option 4)
This is an incorrect option.
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