Light Unit – SPA5

1. Light Unit – SPA5 Study questions Directions: Go through this slide show in presentation mode. Read each question carefully, decide on the best answer, then click enter a second time to see if you were right. If you do well on these questions you will do well on the test.

2. Which of the following is NOT a reason why light rays entering or leaving a transparent material are refracted? • A. The speed of the light rays is changed. • B. The transparent material has density different from air. • C. Light rays change direction when they speed up or slow down. • D. Transparent materials diffuse and scatter light rays.

3. How can the behavior of light best be modeled? • A. waves only • B. particles only • C. both waves and particles • D. both rays and particles

4. What happens when light passes through a transparent block? • A. It reflects when it enters but refracts when it leaves. • B. It reflects when it enters and leaves. • C. It refracts when it enters and leaves. • D. It refracts when it enters but reflects when it leaves.

5. Which of the following ray diagrams correctly shows reflection froma plane mirror?

6. Which of the following statements about reflection is NOT correct? • A. All objects that are visible reflect light. • B. The Law of Reflection applies to any reflected light ray. • C. The Law of Reflection states that the angle of incidence is equal to the angle of reflection. • D. Smooth shiny surfaces reflect more light than rough dull ones.

7. Kondiuses a ray box to make light strike a transparent block. She measures the angle of incidence and angle of refraction and finds that asthe angle of incidence increases, the angle of refraction • A. decreases by the same amount • B. increases by the same amount • C. increases, but not by the same amount • D. decreases, but not by the same amount

8. Which of the following statements about virtual images is correct? • A. The image you see of yourself in a plane mirror is real, not virtual. • B. Virtual images are only visible if they reflect light. • C. A virtual image is formed when light reflected by an object reaches the location of the image in a mirror. • D. Virtual images can be seen but cannot be focused or projected onto a surface.

9. Which of the following statements is NOT correct? • A. Light rays are refracted because their speed changes as they pass from one transparent material to another. • B. Light rays are refracted both as they enter and leave a transparent object. • C. The density of a transparent object affects the speed and direction of light rays passing through it. • D. When light rays strike a transparent object they all pass through and are refracted, none are reflected.

10. Tiokaused ball bearings and water waves to model properties of light andreached the following conclusions. Which of her conclusions is NOTcorrect? • A. Ball bearings adequately model the direction of refraction when velocity increases. • B. Water waves adequately model the direction of refraction when velocity increases. • C. Both ball bearings and water waves adequately model reflection from a surface. • D. Both ball bearings and water waves adequately model refraction with a change in velocity.

11. If Kondi had also measured the angle of reflection she would havediscovered that as the angle of incidence increases the angle ofreflection • A. decreases by an equal amount • B. increases by an equal amount • C. decreases, but not by an equal amount • D. increases, but not by an equal amount

12. Doreen is standing at arms length in front of a bedroom mirror. She can see from her knees to her head but wishes to see her shoes, so she backs away from the mirror several steps and looks again. Which of the following accurately describes what she sees? • A. Doreen can now see a full image of herself, including her shoes. • B. Doreen only sees from her knees to her head, exactly as before. • C. Doreen now can only see from her waist to her neck. • D. Doreen can see a complete image of herself, but it is smaller than before.

13. If a light ray strikes a mirror at 30° to the normal, at what angle to the normal will it be reflected? • A. 0° • B. 15° • C. 30° • D. 60°

14. The change of direction of the light ray takes place because • A. light travels slower in the glass block. • B. light travels faster in the glass block. • C. light is focused by the glass block. • D. light is partially absorbed by the glass block. • The diagram below shows what happens to a ray of light when it leaves the • air (x) and enters a glass block (y). Use the diagram to answer question 11.

15. The greatest change in the speed of light would occur if light passedbetween which of the following two materials? • A. air and diamond • B. glass and diamond • C. air and water • D. transparent plastic and glass • Table 1 shows the refractive indices of five different materials.

16. Which of the diagrams below best illustrates how a beam of light travelsalong an optical fiber?

17. Which of the following diagrams shows how the image of this face will appear in the plane mirror? • The diagram below shows a face looking at a plane mirror.

18. Which of the following pairs comparing the function of eye parts tocamera parts is NOT correct? • A. pupil in eye; aperture in camera • B. iris in eye; shutter in camera • C. cornea in eye; lens in camera • D. retina in eye; film in camera

19. Mirrors and lenses are used in many optical devices. Which of thefollowing is NOT correct? • A. Camera - uses 2 convex lenses • B. Periscope – uses 2 plane mirrors • C. Refracting telescope – uses 2 convex lenses • D. Reflecting telescope – uses 1 convex lens and 1 plane mirror

20. Which of the following would be needed to make a simple refractingtelescope? • A. One concave lens. • B. Two concave lenses. • C. One convex and one concave lens. • D. Two convex lenses.

21. The structure and function of the human eye is most like which of thefollowing optical devices? • A. Telescope • B. Camera • C. Periscope • D. Optical fiber