Question

The object is placed at10cm from the optical centre of the lens having focal length 12xm find the image distance

Answer 1

If lens is a convex lens,

u= -10cm

f = 12cm

v= image distance

1/v  -  1/u  =  1/f

1/v  =  1/f + 1/u

$\frac{1}{v} = \frac{1}{12} + \frac{1}{-10}$

$\frac{1}{v} = \frac{5}{60} + \frac{6}{60}$

$\frac{1}{v} = \frac{-1}{60}$

thus,

v = - 60cm

hope this helps :)