Question

find the position, size and nature of the image formed when an object 2 cm high place a 7.5 cm from a convex lens of focal length 5cm

Answer 1

Mirror formula :

1/u + 1/v = 1/f

1/5 - 10/75 = 1/15

Image distance is 15 cm

Since it is positive, the image is real.

Magnification = image distance ÷ object distance

15 / 7.5 = 2

Magnification = image height ÷ object height

Hi = 2 × 2 = 4 cm