Name: Class: Date: 1. Friction can result in the transfer of protons from one object to another as the objects rub against each other.

Transcription

1 Class: Date: Physics Test Review Modified True/False Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true. 1. Friction can result in the transfer of protons from one object to another as the objects rub against each other. 2. Solids not liquids can be influenced by static charges. 3. Static electricity describes an electric charge that is stationary on the surface of a material. 4. Conductors allow electric charges to move easily through them. 5. Like charges attract and opposite charges repel each other., 6. Charged objects do not attract neutral objects. 7. An object becomes charged if it contains unequal numbers of electrons and protons. 8. Lightning is an extreme example of a static electric discharge. 9. The unit of measurement that refers to the quantity of charge passing through a point in a conducting wire per unit of time is the coulomb. The following diagram illustrates an electrochemical cell with an ammeter and a voltmeter connected in the circuit. 10. In the diagram above, C represents the source for the electrical circuit. 11. The circuit illustrated above would not work if the positions of C and D were reversed. 12. In the circuit illustrated above, the conductor is labelled A. 13. The term used to describe the potential difference across an electric circuit is the load. 1

2 14. If all other factors remain constant, the electrical resistance of a conductor increases with the length of the conductor. 15. A substance that can conduct electricity is known as an electrode. 16. As more resistors are added to a series circuit, the total resistance of the circuit increases. 17. A switch in one branch of a parallel circuit will not affect a lamp in another branch. 18. A parallel circuit requires one power supply for each of the branches in the circuit. 19. The picture of the racetrack is like a series circuit. In a series circuit, electric charges have many paths through which they can flow. 20. In a parallel circuit, the potential difference across each load is equal. 21. Power is measured in units known as joules (J). 22. A 1400 W electric baseboard heater consumes more energy per minute than does a 1000 W kettle. 23. The unit kw h is a measure of energy consumption. Multiple Choice Identify the choice that best completes the statement or answers the question. 24. How will two acetate strips charged in the same way react to each other? a) They will attract one another. b) They will repel one another. c) They will not affect one another. d) They will neutralize one another. 25. When a negatively charged acetate strip and a positively charged vinyl strip are brought together, they will a) attract one another. b) repel one another. c) not affect one another. d) both become negatively charged. 2

3 26. A plastic ball hanging by a string is attracted to a positively charged plastic rod. What can you conclude about the ball? a) It could be neutral or positively charged. b) It is definitely positively charged. c) It is definitely negatively charged. d) It could be neutral or negatively charged. 27. How does a positively charged object become neutralized? a) It loses protons. c) It gains electrons. b) It gains protons. d) It loses electrons. 28. When an uncharged object loses electrons, it becomes a) fully charged. c) neutral. b) negatively charged. d) positively charged. 29. What charge will a material take on if it gains electrons? a) a negative charge c) a neutral charge b) no charge d) a positive charge 30. Which of the following are among the laws of static electricity? I. Similar charges attract. II. Similar charges repel. III. Opposite charges attract. IV. Opposite charges repel. V. Neutral objects are not attracted to charged objects. VI. Neutral objects are attracted to charged objects. a) I, IV, and VI c) II, III, and V b) I, IV, and VI d) II, III, and VI 31. Materials that do not allow a charge to move freely on or through them are called a) conductors. c) balanced. b) unbalanced. d) insulators. 32. Materials that allow charges to flow through them are called a) unbalanced. c) insulators. b) conductors. d) balanced. 33. Sometimes a material is charged by rubbing or touching and the charge remains stationary. This is an example of a) a balanced charge. c) static electricity. b) an unbalanced charge. d) an insulator. The following diagram illustrates the charge on three different objects, A, B, and C. 34. In the illustration above, object A is a) positively charged. c) neutral. b) negatively charged. d) a semiconductor. 3

4 35. Based on the illustration above, if object C is brought close to object B, a) the objects will repel one another. b) the objects will attract one another. c) object C will be neutralized. d) object A will be neutralized. 36. Based on the illustration above, for object C to become positively charged, it would have to a) gain electrons. b) lose electrons. c) be brought together with object B. d) be brought together with object A. 37. In the illustration above, object B is a) uncharged. c) an insulator. b) positively charged. d) negatively charged. 38. Based on the illustration above, object B would be a) attracted to object A and repelled by object C. b) attracted to object C and repelled by object A. c) repelled by object A and attracted to object C. d) none of the above. 39. Which of the following most accurately explains the difference between an insulator and a conductor? a) A conductor traps and holds electrons more readily than an insulator. b) Insulators do not allow charges to move freely through them, but conductors do. c) Insulators are metals, while conductors are usually synthetic materials. d) Rubbing a conductor with fur will cause it to stick to a wall, but rubbing an insulator with fur will not have any effect. 40. Which of the following statements best describes the structure of an atom? a) a positively charged nucleus, consisting of protons and neutrons, orbited by electrons b) electrons and protons within the nucleus, orbited by neutrons c) a dense, positively charged nucleus, orbited by protons and electrons d) negatively charged protons and neutrons in the nucleus, orbited by electrons 41. Many household electric plugs have two prongs. Some household appliances have plugs with three prongs. Which of the following statements best describes the function of this third, rounded prong? a) It allows electricity to flow into the appliance faster. b) It keeps the plug attached to the wall better. c) It allows the appliance to operate at a higher temperature. d) It helps protect against electric shocks and fires by connecting to the grounding wire. 42. Why are household electrical wires covered with rubber or plastic? a) to prevent electric shocks b) to make the wires more flexible c) so that wires can be made in different colours d) to keep the wires warm in cool weather 43. A new tool is being designed for electricians who wire houses. Which material would be the safest to use in the tool s handle to prevent electric shocks? a) copper c) plastic b) aluminum d) carbon 4

5 The following diagram illustrates a simple circuit. 44. What is the best way to measure the current through the circuit illustrated above? a) a voltmeter inserted between the battery and the switch b) an ammeter inserted between the battery and the switch c) an ammeter inserted between the lamp and the battery d) either B or C 45. For current to flow around the circuit illustrated above, which of the following conditions must be satisfied? a) The battery must have sufficient energy stored within it. b) Both wires must be connected to the positive terminal of the battery. c) The switch must be in the closed position. d) Both A and C. 46. In the circuit illustrated above, the current flows a) from the positive terminal of the battery through the circuit to the negative terminal. b) from the negative terminal of the battery through the circuit to the positive terminal. c) only when the switch is open. d) Both B and C. 47. What feature of a river is the best analogy for current in an electric circuit? a) the volume of water that moves past a particular point measured in litres per second b) the depth of the river measured in metres c) the vertical drop between two points along the river measured in metres d) the speed of water flow measured in metres per second 48. What feature of a river is the best analogy for potential difference in an electric circuit? a) the width of the river measured in metres b) the speed of water flow measured in metres per second c) the vertical drop between two points along the river measured in metres d) the volume of water that moves past a particular point measured in litres per second 5

6 49. What instrument is used to measure electric current? a) an ammeter c) an ohmmeter b) a switch d) a voltmeter 50. What is the unit of measurement for electric current? a) the ampere c) the electron b) the charge d) the volt 51. When you measure current, you are measuring the number of a) neutrons that pass a point in 1 s. b) protons that pass a point in 1 s. c) electrons that pass a point in 1 s. d) atoms that pass a point in 1 s. 52. Potential difference is more commonly referred to as a) current. c) joules. b) amperes. d) voltage. 53. The symbol I is used to represent a) load. c) volts. b) current. d) power. 54. When an electric circuit is set up, the main purpose of a source is to provide a) heat. c) resistance. b) current. d) insulation. 55. The part of a complete circuit that converts electricity into other forms of energy is known as the a) control. c) load. b) conductor. d) source. 56. Some circuit elements are best illustrated as a resistor in a circuit diagram. Which list includes only devices that could be represented best as resistors? a) electric motor, toaster, radio b) light bulb, motor, voltmeter c) power supply, battery d) kettle, switch, copper wires 57. Which of the following is not a requirement for an electric circuit? a) a continuous pathway c) a conductor b) a grounder d) a source 6

7 58. In the water system illustrated above, which of the numbered elements is like the conductor in an electric circuit? a) 1 c) 3 b) 2 d) A series circuit consists of two loads and a 6 V power source. Readings are taken to measure the resistance of each load. The 6 V power source is then replaced by a 9 V power source. How does the resistance of each load change after the change in power supply? a) The resistance of each load remains the same. b) The resistance of each load increases by a factor of 1.5. c) The resistance of each load decreases by a factor of 1.5. d) The resistance of the first load increases, but the resistance of the second load decreases. 60. To determine the resistance of an electrical device in a simple electric circuit, you would have to take measurements using a) an ammeter. b) a voltmeter. c) an ammeter and a voltmeter. d) two voltmeters, one for the battery and one for the device. 61. Which of the following best describes Ohm s law? a) Potential difference equals energy divided by charge. b) Resistance equals potential difference divided by current. c) Resistance equals current divided by potential difference. d) Current equals charge divided by time. 62. Which unit of measurement is used for resistance? a) joules per coulomb (J/C) c) volts per ampere (V/A) b) ohms per ampere (Ω/A) d) amperes per ohms (A/Ω) 63. Voltage, current, potential difference, and resistance are all features of an electric circuit. Which of the following terms describes what opposes the motion of electrons? a) Resistance c) Current b) Potential difference d) Voltage 7

8 64. The following diagram illustrates a circuit that consists of a battery, a switch, and a lamp. The battery has a voltage of 9 V and the lamp has a resistance of 6 Ω. What is the current through the circuit? a) 0.67 A c) 1.5 A b) 3 A d) 72 A 65. The following diagram illustrates a circuit consisting of a battery, a switch, and a lamp. What is the effect of doubling the resistance of the lamp without changing the voltage of the battery? a) The current is unchanged. c) The current is doubled. b) The current is halved. d) The current is quadrupled. 66. Many electronic circuits contain resistors that help them work properly. Which of the following is the main risk associated with having resistors in a circuit? a) They make devices move too slowly. b) They heat up and create a fire hazard. c) They make it difficult to control the current. d) They cause the electrons to move too quickly. 67. In a standard flashlight battery, electrons leave the battery from the a) neutral terminal. c) positive terminal. b) negative terminal. d) voltage terminal. 68. The key difference between a dry cell and a wet cell is in the a) conductivity of the electrodes. c) conductivity of the electrolyte. b) state of the electrolyte. d) state of the electrodes. 8

9 69. An electrochemical cell converts a) chemical energy into electrical energy. b) electrical energy into chemical energy. c) chemical energy into light. d) electrical energy into light. 70. Which of the following best describes the movement of electrons around a series circuit? a) The electrons take one of several possible paths. b) The electrons give up equal amounts of energy as they pass through each branch of the circuit. c) The current is higher near the power source than anywhere else in the circuit. d) The electrons follow the same path around the circuit. 71. A series circuit has three 5 Ω resistors. What is the total resistance of the circuit? a) 0.2 c) 15 b) 5 d) Which of the following characteristics do parallel circuits display? I. The potential difference is the same across each branch. II. The sum of the currents through all branches is equal to the total current through the entire circuit. III. The total resistance of the circuit increases as more loads are added in parallel. a) II and III c) III b) I and III d) I and II The following diagram illustrates a circuit consisting of a battery, a switch, and a lamp. 73. In the circuit illustrated above, what will happen to the lamp if a resistor is added to the circuit at point A? a) It will get brighter. c) It will go out. b) It will get dimmer. d) It will remain unchanged. 74. You add a second identical lamp to the circuit illustrated above by connecting it from point B to point C. Which of the following is true? a) The two lamps are of equal brightness, but they are dimmer than the single lamp was. b) The two lamps are of equal brightness, and are as bright as the single lamp was. c) The new lamp is brighter than the original lamp. d) The original lamp is brighter than the new lamp. 9

10 75. The following circuit has three identical lamps connected in parallel. When an electric current is passed through the circuit, a) the lamp closest to the energy source will be the brightest. b) the lamp farthest from the energy source will be the brightest. c) the lamp in the middle will be the brightest. d) the lamps will all have the same brightness. 76. Electrical surges can be caused by a) turning on a large electrical appliance. c) a lightning strike. b) turning off a large electrical appliance. d) all of the above. The following diagram shows four different circuits in which two motors and a lamp are connected to a battery. 77. In which of the circuits shown above will the motors work only when the switch is closed? a) I, II, and III c) I, III, and IV b) I, II, and IV d) II, III, and IV 10

11 78. Of the circuits shown above, which will allow the lamp to light up only when the switch is closed? a) I and II c) I, II, and IV b) I and III d) I, II, III, and IV 79. If a family receives an electric bill of $ for a month, and the power company charges 10 cents per kw h, how much energy did the family use? a) 122 kw h c) kw h b) 1220 kw h d) kw h 80. A current of 16 A passes through a hair dryer when it is connected to a 110 V wall outlet. What is the power of the hair dryer? a) 6.9 W c) 145 W b) 1760 W d) W 81. Which of the following is measured in watts? a) voltage c) current b) power d) resistance 82. A home theatre requires 10 A to operate. What is the power of the theatre when it is connected to a 120 V household circuit? a) 12 W c) 1200 W b) 8300 W d) 83 W 83. How much does it cost to run a 2 kw h freezer for 24 h if the cost of energy is 10 cents per kilowatt-hour? a) $0.48 c) $2.40 b) $1.20 d) $ A 240 W laptop computer requires 10 A to operate. What is the voltage produced by the computer s battery pack? a) 12 V c) 2400 V b) 24 V d) 1200 V 85. The power rating label on a clothes dryer tells you a) how much current the dryer uses per second of operation. b) how much energy the dryer uses per second of operation. c) how the efficiency of this dryer compares to other kinds of dryers. d) how much energy the dryer is likely to use in one year. 86. An MP3 player using two 1.5 V AA cells in series has a total voltage of 3 V. It can withstand a maximum current of 2 A. What is the maximum power of the MP3 player? a) 3 W c) 2.5 W b) 6 W d) 1.33 W 87. If a dishwasher uses J of energy in 30 min, what is the power consumption of this appliance? a) 1.2 W c) 120 W b) 12 W d) 1200 W 88. If a dishwasher consumes 2400 W of power in 60 min, how much energy has been used by this appliance? a) J c) J b) J d) J 11

12 Completion Complete each statement. 89. An arrangement of electrical components through which electrons follow an unbroken path is known as a. 90. Electrons flowing through a conductor constitute an electric. 91. The device shown above is known as a and is used to measure the in a circuit. 92. You can start and stop the flow of current around a circuit by inserting a into the circuit. 93. The of a material is the property that determines how difficult it is to force an electric current through that material. Matching Match each term to one of the following definitions. a) connecting an object to Earth with a conducting wire b) a charge produced by rubbing objects together c) material that offers little or no resistance to the flow of charges d) material through which a charge does not move e) material that holds its electrons loosely 94. static electricity 95. electrical insulator 96. grounding 97. superconductor 98. electrical conductor Match each term to one of the following definitions. a) electron d) nucleus b) proton e) ion c) neutron 99. the part of an atom that is positively charged 100. the part of an atom that is negatively charged 101. the region of an atom that accounts for most of its mass 12

13 102. the part of an atom that has no electric charge 103. an atom that has unequal numbers of protons and electrons Match the term to one of the following diagrams. a) d) b) e) ignore c) f) 104. bulb 105. conducting wire 106. open switch 107. battery 108. closed switch Match the function to the component of a simple circuit. Not all components will be used. a) conducting wire d) switch b) battery e) ammeter c) voltmeter f) load 109. converts chemical energy into electrical potential energy 110. carries current around a circuit 111. provides a means of interrupting the current 112. converts electrical energy into some other form(s) of energy 113. measures the current passing through a part of a circuit 13

14 Physics Test Review Answer Section MODIFIED TRUE/FALSE 1. F, electrons 2. F, solids and liquids 3. T 4. T 5. F, repel each other, attract 6. F, may 7. T 8. T 9. F, ampere 10. T 11. T 12. F, B 13. F, voltage 14. T 15. F, electrolyte 16. T 17. T 18. F, the whole 19. F, only one path 20. T 21. F, watts (W) 22. T 23. T MULTIPLE CHOICE 24. B 25. A 26. D 27. C 28. D 29. A 30. D 31. D 32. B 33. C 34. C 35. B 36. B 1

15 37. B 38. D 39. B 40. A 41. D 42. A 43. C 44. D 45. D 46. B 47. A 48. C 49. A 50. A 51. C 52. D 53. B 54. B 55. C 56. A 57. B 58. B 59. A 60. C 61. B 62. C 63. A 64. C 65. B 66. B 67. B 68. B 69. A 70. D 71. C 72. D 73. B 74. B 75. D 76. D 77. D 78. C 79. B 80. B 81. B 2

16 82. C 83. D 84. B 85. B 86. B 87. D Total time: t = 30 min 60 s 1 min = 1800 s Power is: P = E t = = 1200 W 1200 W of power are consumed. 88. D Time is: t = 60 min 60 s min = 3600 s Energy is: E = Pt = 2400 W 3600 s = J J or J are consumed. COMPLETION 89. circuit 90. current 91. ammeter, current 92. switch 93. resistance MATCHING 94. B 95. D 96. A 97. C 3

17 98. E 99. B 100. A 101. D 102. C 103. E 104. D 105. F 106. A 107. B 108. C 109. B 110. A 111. D 112. F 113. E 4