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

Options

A. `(f+x)/(f)`
B. `(f)/(x)`
C. `sqrt((f)/(x))`
D. `(f^(2))/(x^(2))`

Answer

B

Explanation

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)`.