Question

The focal length of a projector lens is 10 cm. This forms an image at 5 cm of 2 cm x 2 cm slider. The size of image on the screen is _______

Answer 1

k=d_i/f (1), where di is the distance from projector to screen, f is the focal length of the projector
Of (1) k=0.05m/0.1m=0.5
The size of image is 0.5×2cm=1cm
Answer:
1 cm x 1 cm