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The focal length of convex tens is f and...

The focal length of convex tens is `f` and the distance of an object from the principal focus is x. The ratio of the size of the real image to the size of the object is

A

`(f+x)/(f)`

B

`(f)/(x)`

C

`sqrt((f)/(x))`

D

`(f^(2))/(x^(2))`

Text Solution

Verified by Experts

The correct Answer is:
B
Mangnification (m) = `(-v)/(u) = ( (-f)/(f- u)) = (f)/(f - u)`
`(1)/(v) =(1)/(f) - (1)/(u) = (u -f)/(uf) rArr u = (uf)/(u - f)`
here, u = + (f + x)
`therefore " "m = (f)/(f - f -x) = (-f)/(x)`.
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