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A lens with a focal length of 25 cm prod...

A lens with a focal length of 25 cm produces real image of an object at a distance of 50 cm from the lens. At what distance the object placed from the lens?

Text Solution

Verified by Experts

The correct Answer is:
The object is placed at a distance of 50 cm from the lens.
Given: Focal length (f)=25 cm
image distance (v)=50 cm
To find: Object distance (u)
Formula: `(1)/(f)=(1)/(v)-(1)/(u)`
Calculation: From formula,
`(1)/(25)=(1)/(250)-(1)/(u)`
`therefore" "(1)/(u)=(1)/(50)-(1)/(25)=-(1)/(50)`
`therefore" "u=-50 cm`
The negative sign indicates that object is placed on left of the lens.
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