Page 422 - Schaum's Outline of Theory and Problems of Applied Physics

CHAP. 32] LENSES 407

32.10. A button 1 cm in diameter is held 10 cm from a converging lens whose focal length is +25 cm. Find the location,
size, and nature of the image.

32.11. The button of Prob. 32.10 is held 25 cm from the same lens. Find the location, size, and nature of the image.

32.12. The button of Prob. 32.10 is held 40 cm from the same lens. Find the location, size, and nature of the image.

32.13. The button of Prob. 32.10 is held 50 cm from the same lens. Find the location, size, and nature of the image.
32.14. The button of Prob. 32.10 is held 100 cm from the same lens. Find the location, size, and nature of the image.

32.15. A diverging lens with a focal length of −1 m is used to examine a man 1.8 m tall who is standing 4 m away. How
tall does the man appear to be?

32.16. A movie director holds a diverging lens 5 m from an actress and sees her 1/10 of her actual height. Find the focal
length of the lens.

32.17. A camera whose lens has a focal length of 1 m photographs a truck on the ground 7 m below. The image of the truck
on the film is 1.3 mm long. How long is the actual truck?
32.18. A magnifying glass of focal length 75 mm is held 25 mm from a postage stamp. What magnification does it produce?
What is the nature of the image?
32.19. A converging lens has a focal length of 10 cm. (a) How far away from an object should the lens be held to produce
an erect, virtual image magnified three times? (b) What is the image distance?

32.20. A slide projector has a lens whose focal length is 8 in. How far from the lens should the screen be located if a slide
2 in. by 2 in. is to appear 40 in. by 40 in.?

32.21. What is the focal length of a combination of two thin lenses in contact both of whose focal lengths are +8 in.?
32.22. A microscope has an objective of focal length 4 mm which is used with a 15× eyepiece. If the image distance for
the objective is 160 mm, find the magnification of the instrument.
32.23. A telescope has an objective lens whose focal length is 120 cm and an eyepiece whose focal length is 4 cm. (a)
◦
What is the angular magnification of this telescope? (b) The moon has an angular diameter of about 0.5 as seen
from the earth. What is its angular diameter through the telescope? (c) If the image distance is 25 cm, what is the
apparent diameter of the moon as seen through the telescope?

Answers to Multiple-Choice Questions

32.1. (d) 32.9. (b)

32.2. (c) 32.10. (d)
32.3. (a) 32.11. (d)

32.4. (d) 32.12. (d)

32.5. (a) 32.13. (d)

32.6. (b) 32.14. (b)

32.7. (d) 32.15. (d)
32.8. (a) 32.16. (a)