Question
Question: When an object is at distance x and y from a lens, a real image and a virtual image is formed respec...
When an object is at distance x and y from a lens, a real image and a virtual image is formed respectively having same magnification. The focal length of the lens is –
A
B
x – y
C
D
x + y
Answer
Explanation
Solution
The given lens is a convex lens. Let the magnification be m, then for real image
+
= 
... (i)
and for virtual image 
= 
... (ii)
From Eq. (i) and Eq. (ii), we get f = 