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A concave lens of focal length 20 cm pro...

A concave lens of focal length 20 cm product an image half in size of the real object. The distance of the real object is

A

`20cm`

B

`30 cm`

C

`10 cm`

D

`60 cm`

Text Solution

Verified by Experts

The correct Answer is:
A
`m=(f)/(f+u)`
`(1)/(2)=(-20)/(-20+u)` or `-20+u=-40`
or `u=-40 +20` or `u=-20cm`.
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