A photographic slide 24 mm high is to be projected onto a screen 4.8 m high placed 12 m from the lens.
a. (a) Calculate the focal length of a single converging lens that can produce the required image size on the screen.
b. (b) Find the distance from the lens at which the slide should be positioned for a sharply focused image.
c. (c) If, by mistake, a diverging lens of the same focal length is installed in the projector, qualitatively describe the nature, orientation and approximate size of the image that would be obtained on the screen.