1. Clicker Questions for NEXUS/Physics Light: Ray Model

2. Suppose you have a small brightly lit bulb, a mask, and a screen. You see a small circle of light on the screen. What would happen to the spot if you moved the bulb straight upward a bit? A.The spot would stay where it was. B.The spot would move up a bit. C.The spot would move down a bit. D.The spot would move left a bit. E.The spot would move right a bit. F.Something else NEXUS/Physics Clicker Questions

3. Suppose you have two lit bulbs, the top one red and the bottom one blue, a mask and a screen, as shown. What would you see on the screen if you held the bulbs one over the other as shown? A.One purple circle. B.Two circles, one above the other with the top one red, the lower one blue. C. Two circles, one above the other with the top one blue, the lower one red. D.Something else. NEXUS/Physics Clicker Questions

4. You are sitting in a chair looking at two objects that are suspended from the ceiling. It appears to you that object A is above object B. When you stand up, object A appears to be below object B. Which of the two objects is farther away from you? A.Object A B.Object B C.They are both the same distance. D.You can’t tell. It could be either one NEXUS/Physics Clicker Questions

5. I once observed a woman on an airplane at night with a camera. As we flew low over Washington DC she was impressed with the view of the city lights in the dark. She stood back in the aisle and tried to take a picture through the window using her flash. Explain why this is a bad idea and what her pictures are likely to show. NEXUS/Physics Clicker Questions

7. An observer O, facing a mirror, observes a light source S. Where does O perceive the mirror image of S to be located? A.1 B.2 C.3 D.4 E.Some other location F.O cannot see S in the mirror when they are as shown. NEXUS/Physics Clicker Questions

8. I have a small mirror – about 8 inches high – hanging on my wall. When I’m standing right in front of it, I can only see my head. Can I see all of myself at once by moving far back enough? A.Yes B.No C.I can if I … NEXUS/Physics Clicker Questions

9. How large a mirror do you need in order to see your whole body? A.You can see yourself in any size mirror if you go back far enough. B.About half your size. C.As big as you are. D.Some other answer. NEXUS/Physics Clicker Questions

10. What does a flat mirror do to the image? A.Flips it left to right. B.Flips it upside down. C.Does both. D.Does something else. NEXUS/Physics Clicker Questions

11. What will a real image look like if there is no screen? A.Nothing. You won’t be able to see the image without the screen. B.You will still see the image, but it will appear to be floating in front of the mirror. C.You will still see the image, but it will appear to be on the mirror. D.You will still see the image, but it will appear to be behind the mirror like it is with a flat mirror. NEXUS/Physics Clicker Questions

12. If we get very far away from the back of a curved mirror of radius R, where does the image appear to go? Answer using ray analysis and the mirror equation. A.1. R behind the mirror B.2. R/2 behind the mirror C.3. at the mirror (just behind it) D.4. very far behind the mirror NEXUS/Physics Clicker Questions

13. A ray of light is moving from one medium (blue) into another (yellow). Which of the outgoing rays is the most plausible if A. both media have the same n? B. n blue > n yellow ? C. n blue < n yellow ? NEXUS/Physics Clicker Questions

14. What happens if you put a screen at the image distance for a real image? A.You won’t be able to see the image from anywhere. B.You will be able to see the image from anywhere. C.You will be able to see the image on the screen if you are on the same side of the screen as the lens D.You will be able to see the image only if you are lined up to see the object through the lens. NEXUS/Physics Clicker Questions

15. What happens if you put a screen at the image distance for a virtual image? A.You won’t be able to see the image from anywhere. B.You will be able to see the image from anywhere. C.You will be able to see the image on the screen if you are on the same side of the screen as the lens D.You will be able to see the image only if you are lined up to see the object through the lens. NEXUS/Physics Clicker Questions

16. What happens to the image if the object moves a little closer to the lens ? 1.The image will also get closer to the screen. 2.The image will stay where it was before. 3.The image will get farther from the lens. 4.The image will move to the left side of the lens. 5.You can’t tell what will happen without more information. NEXUS/Physics Clicker Questions

17. What happens to the image if the object moves a lot closer to the lens (inside the X)? A.The image will also get closer to the screen. B.The image will stay where it was before. C.The image will get farther from the lens. D.The image will move to the left side of the lens. E.You can’t tell what will happen without more information. NEXUS/Physics Clicker Questions

18. What happens on the screen if you block part of the lens with a cardboard? A.It will block part of the image on the screen. B.It will make the image dimmer but you will see the whole image. C.Something else. D.It depends on where you put the block. NEXUS/Physics Clicker Questions

19. What happens on the screen if you block part of the lens with a cardboard as shown? A.It will block part of the image on the screen. B.It will make the image dimmer but you will see the whole image. C.Something else. D.It depends on where you put the block. NEXUS/Physics Clicker Questions

20. What happens on the screen if you block part of the lens with a cardboard as shown? A.It will block part of the image on the screen. B.It will make the image dimmer but you will see the whole image. C.Something else. D.It depends on where you put the block. NEXUS/Physics Clicker Questions