1. If you plug an electric toaster rated at 110 V into a 220-V outlet, current in the toaster will be
a. twice what it should be.
b. the same as if it were plugged into 110 V.
c. half what it should be.
d. more than twice what it should be.
e. none of the above

2. If you plug an electric toaster rated at 110 V into a 220-V outlet, current in the toaster will be
a. twice what it should be.
b. the same as if it were plugged into 110 V.
c. half what it should be.
d. more than twice what it should be.
e. none of the above

3. When an 8-V battery is connected to a resistor, 2 A of current flows in the resistor. What is the resistor's value?
a. 2 ohms
b. 4 ohms
c. 8 ohms
d. 16 ohms
e. more than 16 ohms

4. When an 8-V battery is connected to a resistor, 2 A of current flows in the resistor. What is the resistor's value?
a. 2 ohms
b. 4 ohms
c. 8 ohms
d. 16 ohms
e. more than 16 ohms

5. The current through a 5-ohm resistor connected to a 150-V power supply is
a. 1A.
b. 10 A.
c. 30 A.
d. 150 A.
e. none of the above

6. The current through a 5-ohm resistor connected to a 150-V power supply is
a. 1A.
b. 10 A.
c. 30 A.
d. 150 A.
e. none of the above

7. A 15-ohm resistor has a 5-A current in it
A 15-ohm resistor has a 5-A current in it. What is the voltage across the resistor?
a. 5 V
b. 15 V
c. 20 V
d. 25 V
e. more than 25 V

8. A 15-ohm resistor has a 5-A current in it
A 15-ohm resistor has a 5-A current in it. What is the voltage across the resistor?
a. 5 V
b. 15 V
c. 20 V
d. 25 V
e. more than 25 V

9. What is the resistance of a toaster that uses 5 A of current when connected to a 120-volt power source?
a. 5 ohms
b. 24 ohms
c. 120 ohms
d. 600 ohms
e. none of the above

10. What is the resistance of a toaster that uses 5 A of current when connected to a 120-volt power source?
a. 5 ohms
b. 24 ohms
c. 120 ohms
d. 600 ohms
e. none of the above

11. If you accidentally grabbed the prongs of a partially plugged-in 120-V electrical plug on a day when your skin resistance was 130,000 ohms, how much current would pass through your body?
a A
b. 120 A
c. 1,083 A
d. 130,000 A
e. 15,600,000 A

12. If you accidentally grabbed the prongs of a partially plugged-in 120-V electrical plug on a day when your skin resistance was 130,000 ohms, how much current would pass through your body?
a A
b. 120 A
c. 1,083 A
d. 130,000 A
e. 15,600,000 A

13. The primary reason a bird can perch harmlessly on bare high voltage wires is that
a. a bird's feet are close together.
b. a bird has a very large electrical resistance.
c. there is no potential difference across the bird's feet.
d. all of the above

14. The primary reason a bird can perch harmlessly on bare high voltage wires is that
a. a bird's feet are close together.
b. a bird has a very large electrical resistance.
c. there is no potential difference across the bird's feet.
d. all of the above

15. Alternating current is made by
a. alternating current and voltage.
b. alternating the direction of voltage of the power source.
c. huge chemical batteries.
d. none of the above

16. Alternating current is made by
a. alternating current and voltage.
b. alternating the direction of voltage of the power source.
c. huge chemical batteries.
d. none of the above

17. Current from a battery is always
a. DC.
b. AC.

18. Current from a battery is always
a. DC.
b. AC.

19. Power outlets in our homes typically have a potential difference of
b. 120 A.
c. 60 A.
d. 240 V.
e. 120 V.

20. Power outlets in our homes typically have a potential difference of
b. 120 A.
c. 60 A.
d. 240 V.
e. 120 V.

21. In 2004, the number of electrons delivered to an average American home by an average power utility was
a. zero.
b. 110.
c. 220.
d. billions of billions.
e. none of the above

22. In 2004, the number of electrons delivered to an average American home by an average power utility was
a. zero.
b. 110.
c. 220.
d. billions of billions.
e. none of the above

23. Electric power is defined as
a. current times voltage.
b. current divided by voltage.
c. current times resistance.
d. resistance times voltage.
e. voltage divided by current.

24. Electric power is defined as
a. current times voltage.
b. current divided by voltage.
c. current times resistance.
d. resistance times voltage.
e. voltage divided by current.

25. How much power is used by a 12-V battery that draws 0.5 A of current?
b. 6 W
c. 12 W
d. 24 W
e. 30 W

26. How much power is used by a 12-V battery that draws 0.5 A of current?
b. 6 W
c. 12 W
d. 24 W
e. 30 W

27. A light bulb is plugged into a 120-volt outlet and has a 0
A light bulb is plugged into a 120-volt outlet and has a 0.7 A current in it. What is the power rating of the light bulb?
a. 12 W
b. 17 W
c. 84 W
d. 120 W
e. 171 W

28. A light bulb is plugged into a 120-volt outlet and has a 0
A light bulb is plugged into a 120-volt outlet and has a 0.7 A current in it. What is the power rating of the light bulb?
a. 12 W
b. 17 W
c. 84 W
d. 120 W
e. 171 W

29. Electrical potential energy is the energy a charged object has because of its
a. momentum.
b. location.
c. mass.
d. motion.
e. volume.

30. Electrical potential energy is the energy a charged object has because of its
a. momentum.
b. location.
c. mass.
d. motion.
e. volume.

31. A small, positively charged object near a positively charged sphere is moved closer to the sphere. The electrical potential energy of the small object
a. stays the same.
b. decreases.
c. increases.

32. A small, positively charged object near a positively charged sphere is moved closer to the sphere. The electrical potential energy of the small object
a. stays the same.
b. decreases.
c. increases.

33. When an electron is brought near a negatively charged sphere, its potential energy increases. The reason this happens is that
a. two like charges go from a position far apart to a position close together.
b. negative charges repel each other.
c. work was done to bring the charges together.
d. none of the above

34. When an electron is brought near a negatively charged sphere, its potential energy increases. The reason this happens is that
a. two like charges go from a position far apart to a position close together.
b. negative charges repel each other.
c. work was done to bring the charges together.
d. none of the above

35. If two negative charges are held close together and then released, the charges will
a. accelerate toward each other.
b. accelerate away from each other.
c. not move.
d. move at a constant speed away from each other.

36. If two negative charges are held close together and then released, the charges will
a. accelerate toward each other.
b. accelerate away from each other.
c. not move.
d. move at a constant speed away from each other.

37. Electric potential is defined as
a. electrical potential energy of a charge multiplied by the quantity of the charge.
b. electrical potential energy of a charge divided by the quantity of the charge.
c. electrical potential energy.
d. gravitational potential.
e. voltage.

38. Electric potential is defined as
a. electrical potential energy of a charge multiplied by the quantity of the charge.
b. electrical potential energy of a charge divided by the quantity of the charge.
c. electrical potential energy.
d. gravitational potential.
e. voltage.

39. A volt is a unit of
a. charge.
b. electric potential.
c. energy.
d. work.
e. current.

40. A volt is a unit of
a. charge.
b. electric potential.
c. energy.
d. work.
e. current.

41. After you rub a balloon on your hair, the balloon will likely be charged
a. to less than 10 volts.
b. to several hundred volts.
c. to several thousand volts.
d. not at all.

42. After you rub a balloon on your hair, the balloon will likely be charged
a. to less than 10 volts.
b. to several hundred volts.
c. to several thousand volts.
d. not at all.

43. In order for there to be a flow of charge from one place to another, there must be a
a. conductor, such as a wire, connecting the two places.
b. potential difference between the two places.
c. Both A and B above

44. In order for there to be a flow of charge from one place to another, there must be a
a. conductor, such as a wire, connecting the two places.
b. potential difference between the two places.
c. Both A and B above

45. In solid conductors, electric current is the flow of
a. positive and negative charges.
b. electrons.
c. negative ions.
d. protons.
e. none of the above

46. In solid conductors, electric current is the flow of
a. positive and negative charges.
b. electrons.
c. negative ions.
d. protons.
e. none of the above

47. An ampere is a
a. unit of resistance.
b. unit of current.
c. type of charge.
d. voltage.
e. current.

48. An ampere is a
a. unit of resistance.
b. unit of current.
c. type of charge.
d. voltage.
e. current.

49. An example of a voltage source is
a. a dry cell.
b. a generator.
c. a car battery.
d. rubbing a rubber rod with fur.
e. all of the above

50. An example of a voltage source is
a. a dry cell.
b. a generator.
c. a car battery.
d. rubbing a rubber rod with fur.
e. all of the above

51. Electrical resistance in a wire depends on the wire's
a. thickness.
b. conductivity.
c. length.
d. all of the above
e. none of the above

52. Electrical resistance in a wire depends on the wire's
a. thickness.
b. conductivity.
c. length.
d. all of the above
e. none of the above

53. Compared to thin wires, electrical resistance in thick wires is
a. less.
b. the same.
c. greater.

54. Compared to thin wires, electrical resistance in thick wires is
a. less.
b. the same.
c. greater.

55. For most conductors, as their temperature increases, their resistance
a. decreases.
b. increases.
c. stays the same.

56. For most conductors, as their temperature increases, their resistance
a. decreases.
b. increases.
c. stays the same.

57. Electrical resistance is measured in
a. volts.
b. joules.
c. watts.
d. amperes.
e. none of the above

58. Electrical resistance is measured in
a. volts.
b. joules.
c. watts.
d. amperes.
e. none of the above

59. An electric heater is rated at 300 W for use in a 110-V circuit
An electric heater is rated at 300 W for use in a 110-V circuit. The circuit breaker in the circuit can handle 12 A of current. How many heaters can be safely operated in the circuit?
a. 2
b. 3
c. 4
d. 5
e. more than 5

60. An electric heater is rated at 300 W for use in a 110-V circuit
An electric heater is rated at 300 W for use in a 110-V circuit. The circuit breaker in the circuit can handle 12 A of current. How many heaters can be safely operated in the circuit?
a. 2
b. 3
c. 4
d. 5
e. more than 5

61. What is electrical resistance
What is electrical resistance? What characteristics of a wire determine its resistance? How does resistance normally vary with temperature?
What is the difference between direct current and alternating current? When we plug a light bulb into a wall outlet, where do the electrons come from?