Question

Draw a ray diagram to show the formation of image by convex lens of focal length 10cm when a 5 cm tall object is placed in front of lens. at distance of (a) 6cm (b) 15cm

Answer 1

Here,

Object distance, u = -16 cm

Focal length, f = 24 cm

Height of object, h = 4 cm

Image distance = v

Now,

1/f = 1/v – 1/u

=> 1/24 = 1/v + 1/16

=> v = -48 cm [virtual image formed on the same side of the object]

Magnification, m = v/u = -48/(-16) = 3 [image is virtual and magnified]

So, height of image = h × m = (4)(3) = 12 cm

A virtual and magnified image of height 12 cm is formed on the same side of the object.