Chapter 25 Multiple Choive Sample Problems

Chapter 25 Multiple Choive Sample Problems Answers: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. b c c d b a b b b b a b d c c d d 1. Compare two diverging lenses similar except that lens B is rated at 20 diopters, whereas lens A is rated at 10 diopters. The focal length of lens B is a. one-fourth of the focal length of lens A. b. one-half of the focal length of lens A. c. twice the focal length of lens A. d. four times the focal length of lens A. 2. If a person's eyeball is too short from front to back, the person is likely to suffer from a. astigmatism. b. spherical aberration. c. farsightedness. d. nearsightedness. 3. In which of the following ways is a camera different from the human eye? a. The camera always forms an inverted image, the eye does not. b. The camera always forms a real image, the eye does not. c. The camera utilizes a fixed focal length lens, the eye does not for the camera, the image magnification is greater than one, but for the eye the magnification is less than one. e. A camera cannot focus on objects at infinity but the eye can. 4. Farsightedness can usually be corrected with a. b. c. d. 5. 6. cylindrical lenses. achromatic lenses. diverging lenses. converging lenses. Nearsightedness can usually be corrected with a. converging lenses. b. diverging lenses. c. achromatic lenses. d. cylindrical lenses. The principal refraction of light by the eye occurs at the a. cornea. b. lens. c. retina. d. iris. 7. A near-sighted person has a far point of 18 cm. What lens (in diopters) will allow this person to see distant objects clearly? a. +5.6 D b. -5.6 D c. +0.056 D d. -0.056 D 8. The near point of a farsighted person is 100 cm. She places reading glasses close to her eyes, and with them she can comfortably read a newspaper at a distance of 25 cm. What lens power is required? a. +2.5 D b. +3.0 D c. +3.2 D d. -2.0 D 9. What power lens is needed to correct for farsightedness where the uncorrected near point is 75 cm? a. -2.7 D b. +2.7 D c. +5.3 D d. None of the above 10. A person cannot see clearly objects more than 70.0 cm away. What power of lens should be prescribed if the glass is to be worn 1.00 cm in front of the eye? a. b. c. d. 1.45 D -1.45D 0.0145 D -0.0145 D 11. The closest distance at which an eye can see objects clearly is a. the near point b. the far point c. nearsightness d. farsightness 12. The longest distance at which an eye can see objects clearly is a. the near point b. the far point c. nearsightness d. farsightness 13. A nearsighted person wears glasses whose lenses have power of -0.15 D. What is the person's far point if the glasses are very close to the eyes? a. 1.5 m b. 3.3 m c. 6.0 m d. 6.7 m 14. If a farsighted person has a near point of 120 cm, what power of glasses should be prescribed? a. 0.83 D b. -0.83 D c. 3.2 D d. -3.2 D 15. A magnifying lens has a focal length of 10 cm. A person has a near point of 25 cm. What is the magnification of the lens for that person when their eyes are focused at their near point? a. 1.5 b. 2.5 c. 3.5 d. 4.5 16. A compound microscope has an objective with a focal length of 5.00 mm and an eyepiece of focal length 4.00 cm. If the two lenses are separated by 20.0 cm, what is the total magnification? a. 12.5 b. 25.0 c. 125 d. 250 17. A compound microscope has a 18-cm barrel and an objective with a focal length of 8.0 mm. What is the focal length of the eyepiece to give a total magnification of 240? a. 0.13 cm b. 1.5 cm c. 1.9 cm d. 2.3 cm