Question

a convex lens has a focal length 25 CM calculate the distance of the object from the lens if the image is to be formed on opposite side of the lens at a distance of 75 cm from the lens what will be the nature of the image

Answer 1

1/d +1/d'=1/f.by the sign arrangement sgn of d'is negative.

So 1/d-1/d'=1/f.

Now the calculations:1/d-1/75=1/25

Solution is d=18,75cm.

Image is virtual, straight, and larger.