Question

An object placed 45cm from a lens forms an image on a screen 90cm on the other side of the lens. Use the lens formula to find the nature and focal length of the lens. what is the size of the image if the object is 5cm in height?​

Answer 1

Explanation:

u=-45cm

v=90cm

Since the image is virtual therefore, it must be a convex lens

1/f = 1/v - 1/ u

1/f = (1/90) - (- 1/45)

1/f = 1/30

f = 30

m = v/u

m = 90 / - 45

m= -2

m = h'/h

-2 = h' / 5

h = - 10 cm