Question

John has two convex lenses, two concave lenses, and one tube whose length is adjustable. The focal lengths of the convex lenses are 10 cm and 30 cm, respectively. The focal lengths of the concave lenses are 5 cm and 25 cm, respectively. John would like to make a telescope by attaching two lenses at the two sides of the tube.

(a) Assuming John only uses convex lenses, what is the maximum lateral magnification would be? Please draw the corresponding diagram about the incident light and related images through lenses for the combination.

(b) Assuming John uses one convex lens and one concave lens, is it possible to magnify the image made by incident light? If possible, what is the maximum lateral magnification? Please draw the corresponding diagram about the incident light and related images through lenses for the combination.

(c) Assuming that the tube has limited length and can only be stretched as long as 15 cm. Under this circumstance, would John still make a combination of lenses to magnify the image made by incident light? If possible, what would the maximum lateral magnification be? Please draw the corresponding diagram about the incident light and related images through lenses for the combination.

Answer 1

Answer