Lesson Print Name _______________________________________________ Date ________________ Class______________ Chapter 17, continued 17. In the equation for Ohm’s law, what do the letters I, V, and R stand for? 18. Who was Georg Ohm? c. an inventor d. an author CHAPTER 17 a. an electrician b. a teacher 19. If you know the current produced in a wire and the voltage applied, you can calculate the resistance of the wire. True or False? (Circle one.) Electric Power (p. 437) 20. Electric power is expressed in a. ohms. b. volts. ▼ ▼ ▼ c. amperes. d. watts. 21. Light bulbs may be labeled “100 W” or “40 W.” This describes a. b. c. d. how how how how long they burn. they are disposed of. fast the light travels. bright they glow. 22. A television uses more power than a hair dryer. Copyright © by Holt, Rinehart and Winston. All rights reserved. Menu True or False? (Circle one.) Measuring Electrical Energy (p. 438) 23. In the equation for electrical energy, what do E, P, and t stand for? 24. What do electric meters measure? a. power b. voltage c. current d. energy Review (p. 439) Now that you’ve finished Section 3, review what you learned by answering the Review questions in your ScienceLog. Section 4: Electric Circuits (p. 440) 1. An electric circuit always begins and ends in the same place. True or False? (Circle one.) DIRECTED READING WORKSHEETS 129 Print Lesson Name _______________________________________________ Date ________________ Class______________ Chapter 17, continued Parts of a Circuit (p. 440) 2. Which of the following are parts of all electric circuits? (Circle all that apply.) a. a load b. an energy source c. wires d. a switch 3. A opens and closes a circuit. Types of Circuits (p. 441) 4. A circuit has all parts connected in a single loop. A ent loads on separate branches. circuit has differ- 5. A string of holiday lights wired together in series has a burnedout bulb. Why do all of the lights go out? 6. If a break occurs in one of the loops of a parallel circuit, current will not run through the other loops. True or False? (Circle one.) Household Circuits (p. 444) 7. Which of the following may cause a circuit failure? (Circle all that apply.) a. water b. broken wires c. too many loads d. excess insulation 8. As more loads are added to a parallel circuit, the entire circuit draws more current. True or False? (Circle one.) 9. How does a fuse disrupt the flow of charges when the current is too high? a. b. c. d. A metal strip warms up and bends away from the circuit wires. A metal strip warms up and melts, leaving a gap. A metal strip changes from a conductor to an insulator. None of the above 10. Circuit breakers are inconvenient because breakers must be replaced when they are tripped. True or False? (Circle one.) Review (p. 445) Now that you’ve finished Section 4, review what you learned by answering the Review questions in packet. 130 HOLT SCIENCE AND TECHNOLOGY Copyright © by Holt, Rinehart and Winston. All rights reserved. Menu Lesson Print Name _______________________________________________ Date ________________ Class______________ Chapter 17, continued 17. In the equation for Ohm’s law, what do the letters I, V, and R stand for? I stands for current, V is for voltage, and R is for resistance. 18. Who was Georg Ohm? c. an inventor d. an author CHAPTER 17 a. an electrician b. a teacher 19. If you know the current produced in a wire and the voltage applied, you can calculate the resistance of the wire. True or False? (Circle one.) Electric Power (p. 437) 20. Electric power is expressed in a. ohms. b. volts. ▼ ▼ ▼ c. amperes. d. watts. 21. Light bulbs may be labeled “100 W” or “40 W.” This describes a. b. c. d. how how how how long they burn. they are disposed of. fast the light travels. bright they glow. 22. A television uses more power than a hair dryer. Copyright © by Holt, Rinehart and Winston. All rights reserved. Menu True or False? (Circle one.) Measuring Electrical Energy (p. 438) 23. In the equation for electrical energy, what do E, P, and t stand for? E stands for electrical energy, P is for power, and t is for time. 24. What do electric meters measure? a. power b. voltage c. current d. energy Review (p. 439) Now that you’ve finished Section 3, review what you learned by answering the Review questions in your ScienceLog. Section 4: Electric Circuits (p. 440) 1. An electric circuit always begins and ends in the same place. True or False? (Circle one.) DIRECTED READING WORKSHEETS 129 Print Lesson Name _______________________________________________ Date ________________ Class______________ Chapter 17, continued Parts of a Circuit (p. 440) 2. Which of the following are parts of all electric circuits? (Circle all that apply.) a. a load b. an energy source 3. A switch Types of Circuits 4. A c. wires d. a switch opens and closes a circuit. (p. 441) series circuit has all parts connected in parallel a single loop. A ent loads on separate branches. circuit has differ- 5. A string of holiday lights wired together in series has a burnedout bulb. Why do all of the lights go out? The burned-out bulb is a break in the circuit, so the circuit is no longer a closed path through which electric charges may flow. 6. If a break occurs in one of the loops of a parallel circuit, current will not run through the other loops. True or False? (Circle one.) Household Circuits (p. 444) 7. Which of the following may cause a circuit failure? (Circle all that apply.) a. water b. broken wires c. too many loads d. excess insulation 8. As more loads are added to a parallel circuit, the entire circuit draws more current. True or False? (Circle one.) 9. How does a fuse disrupt the flow of charges when the current is too high? a. b. c. d. A metal strip warms up and bends away from the circuit wires. A metal strip warms up and melts, leaving a gap. A metal strip changes from a conductor to an insulator. None of the above 10. Circuit breakers are inconvenient because breakers must be replaced when they are tripped. True or False? (Circle one.) Review (p. 445) Now that you’ve finished Section 4, review what you learned by answering the Review questions in your ScienceLog. 130 HOLT SCIENCE AND TECHNOLOGY Copyright © by Holt, Rinehart and Winston. All rights reserved. Menu