Question

A convex lens of focal length 30 cm produces a real image three times magnified. Find the object distance.
Please answer the question.
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Answer 1

Answer:

The object distance is 30 cm

Explanation:

Let the object distance be x( i.e. u= -x)

Magnification m=-v/u

3 =-v/-x

v=3x

Using lens formula

1/v-1/u=1/f

1/3x- 1/-x =1/30

4/3x=1/30

x=30 cm