Matter & Energy Pretest B
38 Points
«This pretest covers concepts 49 through 94 and the pictures on pages 25-27 in the lab booklet.
«Write your answers on your own paper. Do not write on this test.
«On the left margin beside each answer, write the concept number showing where you found the answer. If the answer is found in pages 25-27, write the page number. Except for the bonus, these questions will follow the order of the concept section.
«Write short answers. You do not need complete sentences.
«When you have finished taking this test put your answer sheet in the assignment tray, and return this test to the file folder box.
1. What happens to gasoline when it is burned in a car engine?
2. What are the two main differences between chemical and nuclear energy? (2 points)
3. What is the difference between thermal energy and temperature?
4. According to the second law of thermodynamics, how does heat always flow?
5. What are the two main differences between a solid, liquid, and gas?
6. What is the difference between static and current electricity?
7. Why do lights sometimes flicker (turn on and off) when there is a short circuit?
8. What is Ohm’s Law?
9. If a simple circuit has a voltage of 120v and a current flow of 5A, what is the circuit’s resistance? Include the proper unit.
10. What is the power of a circuit with 120v and 200A? Include the proper unit.
11. What is an advantage and disadvantage of using a series circuit? (2 points)
12. What is an advantage and disadvantage of using a parallel circuit? (2 points)
13. What remains constant and what changes in a series circuit? In a parallel circuit? (2 points)
14. Why is direct current not used to power our homes and cities?
15. What type of energy is infrared? How fast does it travel through space?
16. Give an example of a conversion of chemical energy into mechanical energy.
17. Where does all energy come from?
18. Why it is impossible for systems to be 100% efficient?
19. What is a closed system? Give an example.
20. What is an open system? Give an example.
21. What is the difference between renewable and nonrenewable energy?
22. Burning wood in a fireplace is what type of energy source?
23. What is the cheapest way to produce electricity in the U.S.?
24. What determines how much energy a wind turbine can produce?
25. Where are the most efficient geothermal power plants located?
26. What determines how much energy a solar collector can produce?
27. What is the largest of source of energy for the U.S.?
28. What does an oil refinery do?
29. How is natural gas used in the U.S.?
30. What is the primary source of electricity in the U.S.?
31. Why do most scientists consider nuclear power plants to be environmentally friendly or clean?
32. What is another name for propane?
33. How could we tell if there was a natural gas or propane leak since these gases do not have a color, smell, or taste to them?
Bonus
34. Two resistors, a 8.0 Ω and a 4Ω , are connected in series across a 24V battery. What is the current in the circuit? What is the voltage drop across each resistor? Show your work! If the 4.0 Ω is replaced by another 8.0 Ω will the current increase, decrease, or remain the same? (3 points)
35. Three resistors, 40 Ω , 10 Ω , and 20 Ω, are connected in parallel across a 80V battery. Find the current through each branch of the circuit.
36. Make a chain of energy conversions at least four long that you might find anywhere. Each energy type must change into another type of energy. Use arrows to show the conversions and separate each item in your system. Use the example below to help. Don’t copy the example!
gasoline chemical energy è thermal energy by ignition inside the engine è mechanical energy by pushing down the piston è electrical energy by turning the fan motor è mechanical energy by the fan moving è sound energy from the air blowing