Question

A 4.0-cm-tall object is 23 cm in front of a converging lens that has a 40 cm focal length.

Calculate the image position.

Calculate the image height.

Answer 1

Solution-

From the question we have

focal length, f = 40 cm (Given in the question)

A)

the object distance , do = 23 cm

let us assume the image distance be di

using the lens formula

1/f = 1/di + 1/do

1/40 = 1/di + 1/23

di = -54.11 cm

the image distance is 54.11 cm

B)

the image height , hi = ho * ( -di/do)

hi = 4*( - 54.11/23)

hi = 9.41 cm

the image height is 9.41 cm