9. Which of the following is the correct relationship among power, current, and voltage?. a. P = I/V c. P = I x V b. V = P x I d.

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1 Name: Electricity and Magnetism Test Multiple Choice Identify the choice that best completes the statement. 1. Resistance is measured in a unit called the. a. ohm c. ampere b. coulomb d. volt 2. The statement that current is equal to the voltage potential difference divided by the resistance is known as. a. Einstein s equation c. Newton s Law b. Faraday s Law d. Ohm s Law 3. A path that allows only one route for an electric current is called a. a. parallel circuit c. parallel current b. series circuit d. series current 4. Electric charge that has accumulated on an object is referred to as. a. circuit electricity c. current electricity b. current circuit d. static electricity 5. A circuit that has two or more branches for electrons to follow is a (n). a. circuit diagram c. electron diagram b. parallel circuit d. series circuit 6. A static discharge differs from an electric current in that a static discharge. a. involves the movement of ions as well as electrons b. is a flow of electrons c. lasts for only a fraction of a second d. results because a force is exerted on the electrons 7. A material through which electrons do not easily flow is a (n). a. insulator c. conductor b. fuse d. transformer 8. If the leaves of an electroscope spread apart, it indicates that. a. the leaves of an electroscope are neutral b. the leaves of the electroscope have received a charge c. no charge is moving through the electroscope d. there is static electricity in the electroscope 9. Which of the following is the correct relationship among power, current, and voltage?. a. P = I/V c. P = I x V b. V = P x I d. E = P x t 10. Which of the following is a device designed to open an overloaded circuit and prevent overheating. a. circuit breaker c. resistor b. magnet d. transformer 11. Current that does not reverse direction is called. a. alternating current c. a fused current b. circuit current d. direct current 12. The location of the strongest magnetic forces is the. a. magnetic poles c. magnetic fields b. magnetic domains d. electromagnets 13. Currents that reverses direction in a regular pattern is called. a. alternating current c. direct current b. circuit current d. magnetic current 14. Objects that keep their magnetic properties for a long time are called. a. electromagnets c. permanent magnets b. magnetic domains d. temporary magnets 1

2 2 15. The function of an electric motor is to change. a. electrical energy to mechanical energy b. electrical energy to chemical energy c. chemical energy to electrical energy d. mechanical energy to electrical energy 20. The diagram shows a negatively charged balloon. When the balloon is brought near some paper, the papers are attracted to the balloon by means of and become. 16. The current that flows in an electric circuit carries. a. chemical energy c. thermal energy b. mechanical energy d. electrical energy 17. The atoms in a magnet are. a. arranged randomly b. aligned according to magnetic fields c. negatively charged d. positively charged 18. When a plastic rod is rubbed with fur, the plastic rod becomes negatively charged. Which statement explains the charge transfer between the plastic rod and the fur?. a. Protons are transferred from the plastic rod to the fur b. Protons are transferred from the fur to the plastic rod c. Electrons are transferred from the plastic rod to the fur d. Electrons are transferred from the fur to the plastic rod 19. How do electrically charged objects affect neutral objects when they come in contact? a. Electrons move from negatively charged objects to neutral objects b. Electrons move from neutral objects to negatively charged objects c. Protons move from positively charged objects to neutral objects d. Protons move from neutral objects to positively charged objects a. induction, positive b. conduction, positive c. induction, negative d. conduction, negative 21. A series circuit has a 6-V battery and 3 ohms of resistance. How much current will flow through the circuit?. a. 0.5 A c. 2 A b. 3 A d. 18 A 22. What voltage is required to run a 45- watt light bulb if the current is 0.5 ampere? a. 90 volts c. 120 volts b. 45 volts d. 225 volts 23. How much current is used by a 120-V refrigerator that uses 650 W of power? a A c. 120 A b. 78,000 A d. 5.4 A 24. Lighting is. a. a build up of neutrons b. harmless c. a high-voltage electric current d. a large discharge of static electricity 25. One source of constant electric current is a _. a. coulomb b. dry cell (battery) c. switch d. transformer

3 26. Which of the following is a conductor?. a. glass b. wood c. iron d. plastic 31. The drawing shows two uncharged lightweight plastic balls suspended by thin, insulating threads. Ball 1 is given a positive charge. Ball 2 is given an equivalent negative charge Resistance in wires causes electrical energy to be converted into which form of energy? a. chemical energy b. nuclear energy c. sound d. thermal energy 28. The electric force between two charged objects depends on which of the following? a. their masses and their distance of separation b. their speeds c. their charge and their distance of separation d. their masses and their charge Which diagram best shows how the balls will react after becoming charged? 29. An object becomes positively charged when which of the following occurs? a. loses electrons b. loses protons c. gains electrons d. gains neutrons 30. Which of the following DOES NOT provide a voltage or potential difference in a circuit? a. wet cell b. wires c. electrical outlet d. dry cell or battery

4 4 32. Three light bulbs are connected to a 120-V potential difference. Ammeters are placed at four locations labeled #1, #2, #3, and # Which is the correct diagram for a parallel circuit with three light bulbs powered by a 24- V battery? At which location will the current be greatest? a #1 b #2 c #3 d#4 33. The symbol Ω represents a. volts b. ohms c. amperes d. coulombs 34. Which magnetic pole is located in Northern Canada? a. north b. south c. positive d. negative 35. Which best describes a circuit is series? a. different parts are on separate branches. b. current values are different at various points in the circuit. c. electrons may take several paths. d. electrons have only one path at all times. 36. Which statement is true about parallel circuits? a. they contain separate branches through which current can flow. b. they are usually called open circuits. c. they provide one path through which current can flow. d. they cease to function when one part of the circuit is disconnected. 38. The diagrams represent two complete circuits. A 9-V battery is connected to two light bulbs as shown. Which statement best describes what will happen? a. the light from circuit A will be brighter because each light bulb adds its current to the other light bulb b. the light from circuit B will be brighter because each light bulb has a direct path to both poles of the battery c. The light from Circuit A will be dimmer because each light bulb has a direct path to both poles of the battery d. the light from circuit B will be dimmer because each light bulb must share its current with the other light bulb

5 39. A motor has a current of 2A flowing through it when it is powered with a 12-V battery. What is the power used by the motor? a. 0.16W b. 6 W c. 14 W d. 24 W 43. This diagram represents a closed circuit A light bulb with a resistance of 100 ohms is plugged into a 120-volt outlet. What is the current flowing through the bulb? a ampere b. 1.2 amperes c. 20 amperes d. 220 amperes 41. A sheet of paper is positioned to completely cover a bar magnet. Iron fillings are then gently sprinkled on the paper. What does the pattern created by the iron fillings indicate? a. the stronger of the two poles b. the distance between the two poles c. the midpoint of the area between the two poles d. the magnetic field created by the poles 42. Which statement BEST explains why there could be a force of attraction between two electrically charged objects? a. because they have like charges b. because they have unlike charges c. because they have the same number of protons d. because they have the same number of electrons How much current flows through this circuit? a. 0.5 A b. 2 A c. 18 A d. 72 A 44. A student coiled wire around a nail, attached both ends to a 1.5-V battery, and attempted to lift paper clips with the nail. Number of turns of wire Results Paper clips picked up What is a valid conclusion for this investigation? a. increasing voltage increases electromagnetic strength b. increasing the number of turns of wire decreases the electromagnetic strength c. increasing the number of turns of wire increases the electromagnetic strength d. increasing the number of turns of wire has no effect on electromagnetic strength

6 6 45. A flashlight bulb connected to a 6-V battery draws a 0.5 A current. What is the power used by the flashlight bulb? a) 1.25 W b) 3 W c) 6.5 W d) 12 W 46. A student performed an experiment to determine the number of paper clips that are attracted to an electromagnet as the amount of current changes. Data Table Current Number of paper clips 5A A A A 80 Which graph best describes the relationship between magnetism and electrical current? 47. Which statement best describes a bar magnet that has been broken into two pieces? a. both pieces have lost their magnetic poles b. one piece has a north pole only, and the other piece has a south pole only c. each piece has both a north and a south pole d. both pieces have a north pole only 48. A magnet is moved back and forth through a loop of wire as shown below. What will happen as the magnet is moved back and forth as shown? a. the wire will attract the magnet b. the magnet will attract the wire c. the galvanometer needle will stay at 0 on the scale d. the galvanometer needle will move back and forth 49. How could 3 magnets be arranged endto-end so that there will be no attraction between them?

7 50. The diagram shows two copper spheres. Sphere 1 is negatively charged, and Sphere 2 is neutral. 53. A student builds an electromagnet using variable power source and 40 turns of wire. The electromagnet is used to pick up metal paper clips. The student changes the voltage and counts the number of clips that are picked up. Which table below could represent the data the student collected? 7 What will be the result when the two spheres touch? a. sphere 1 will become positively charged b. sphere 2 will become positively charged c. both spheres will become negatively charged equal to the initial charge of sphere 1 d. both spheres will become negatively charged less than the initial charge of sphere A series circuit has a current of 3A. The circuit contains a 12 resister. What is the voltage of the circuit? a V b. 4 V c. 15 V d. 36 V 52. If the north poles of two bar magnets are brought together, which is true? a. the two north poles will repel each other b. the two north poles will attract each other c. no force will be experienced between the two magnets d. one north pole will become the south pole due to the interaction. 54. This diagram represents a closed circuit with three light bulbs and a 10 Volt battery. If bulb #3 burns out in the circuit, what will most likely happen? a. bulb 1 and bulb 2 will continue to glow b. bulb 1 and bulb 2 will not glow as brightly c. bulb1 will glow, but bulb 2 will not glow d. bulb 1 and bulb 2 will not glow

8 8 Use figure 7-1 below to complete #55-58 Figure The circuit in an appliance is 7A and the voltage difference is 120V. How much power is being supplied to the appliance? a W c. 840 W b W d W Circuit A Circuit B 55. Circuit is wired in series. 56. Circuit is wired in parallel. 57. Circuit represents the way homes are usually wired so that when one part of the circuit is interrupted the entire circuit is not broken. 58. Circuit is the type of circuit that causes an entire string of decorative lights to go out when one of the bulbs burns out. 59. A circuit has a resistance of 6Ω. What voltage difference will cause a current of 2.1 A to flow in the circuit? a V c V b V d. 3.9 V 60. How many amperes of current will flow in a circuit if the voltage difference is 5V and the resistance in the circuit is 2Ω? a. 10 A b. 0.5 A c. 2.5 A d. 3 A 62. What is the current into a microwave oven that requires 700W of power if the voltage difference is 120V? a. 840 A c A b A d A 63. What is the voltage difference in a circuit that uses 2420 W of power if 11A of current flows into the circuit? a. 220 V c V b V d. 22 V 64. What is the current in a toaster if the toaster uses 2000 W of power when plugged into a 110-V wall outlet? a. 2 A c. 22,000 A b. 18 A d A 65. What is the voltage in a dryer if the dryer uses 4200 W of power when plugged into a 22.0-A wall outlet? a. 220V c. 924V b. 19V d. 190V