Question

A luminous object is placed at a distance of 1 metre from a screen.Its image is obtained on the screen by a convex lens.Find the focal length of the lens if the linear magnification is 3​

Answer 1

Answer:

WE HAVE MAGNIFICATION AS M== V/ U

M== hi/ ho

by using magnification formula we will get V= -3

by using this u will get focal length 1/F= 1/v -1/u

F= 3/2