Question

The product and sum of object distance and focal length of a convex are -150 cm and -5 cm respectively. Find the image distance and nature of images

Answer 1

Answer; as it was given that U+f= -5-----(i)  

and

Uf=-150.....U=-150/f-----(ii)

then putting the value of equ^n 2in 1 we get f=10 cm and-15 cm

as it has told about convex lens so f will be positive f=10 cm then U=-15 cm

using the lens formula 1/v=1/f+1/U

                                     =>1/v=1/10-1/15=5/150=1/30

so v=30 cm

nature of img; height of img is equal to the twice of height of obj.[obj dist is -1/2 of img dist]

magnification=-2

real and inverted