PHYS 101 Quiz 7

PHYS 101 Quiz 7 Liberty University

1. Voltage can also be called
2. The type of EM wave having the highest frequency is
3. The type of EM radiation that has wavelength just a bit longer than that of visible light is
4. A quantity that measures the opposition to the flow of charge is
5. When a 12-volt car battery is short circuited with a wire, the current drawn
6. from the battery is 100 amperes. The resistance of the wire is
7. The electric field shown is produced by a single point charge at the center of the picture.
8. The type of EM radiation emitted when high speed electrons decelerate as they are smashed into a metal target is
9. Why do we use fuses?
10. For a body emitting blackbody radiation, the total power emitted is proportional to the 4th power of the body’s absolute temperature:
11. A coil of wire is connected to a galvanometer. When a bar magnet is moved in and out of the coil, the galvanometer records a current. The current results because
12. A superconductor expels any magnetic field from its interior. This is called
13. Lightning is dangerous to humans because lightning strokes
14. Global warming
15. The greenhouse effect occurs because
16. A heater is rated at 1200 watts for a 120-volt source.
17. The ozone layer absorbs infrared radiation from sunlight.
18. Higher frequency radio waves are reflected by the ionosphere.
19. Semiconductor technology has been the basis for many new electronic devices.
20. The increase in the amount of carbon dioxide in the atmosphere is contributing to the greenhouse effect.
21. Current is the opposition to the flow of charge.
22. A battery operating a large flashlight produces a current of 2 amperes in a light bulb that has a resistance of 4 ohms. The voltage of the battery is 2 volts.
23. The ionosphere reflects high frequency radio waves.
24. For a body emitting blackbody radiation, the total power emitted is proportional to the 4th power of the body’s absolute temperature:
25. If an electric toaster operating on 120 volts draws a current of 6 amperes, the resistance of the toaster is 20 ohms.
26. The frequency of visible light determines its color.
27. Select the closest matching pairs possible. 3 pts for each response. Write Ohm’s Law A potentiometer is a variable resistor that can be adjusted given the needs of the application. For a 24-volt circuit compute the resistance that should be set to obtain the following current levels: