The distance between a screen and an object is 120 cm. A convex lens is placed closed to the object and is moved along the line joining object and screen, towards the screen. Two sharp images of the object are found on the screen. The ratio of magnification of two real images is 1 : 9. Then -
Text Solution
Verified by ExpertsThe correct answer is:
CHECK THE SOLUTION.
(a, b)
x + y = 120 … (i)
= m 1
= m 2
= 
3x = y
∴ x + 3x = 120 ⇒ x = 30, y = 90
= 
⇒ f = 22.5 cm
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