Physics Chapter 23

1. Modern automobile headlights are connected in

Parallel

Perpendicular

Series

None of these

2. The current through a 10-ohm resistor connected to a 120-V power supply is

1 A

10 A

12 A

120 A

None of these

3. The headlights, radio, and defroster fan in an automobile are connected in

Series

Parallel

4. An ampere is a unit of electrical

Pressure

Current

Resistance

All of these

None of these

5. What is the power rating of a light bulb if 0.8 A flow through it when it is connected to a 120-volt outlet?

12 W

15 W

60 W

96 W

120 W

6. When a 10-V battery is connected to a resistor, the current in the resistor is 2A. What is the resistor's value?

2 ohms

5 ohms

10 ohms

20 ohms

More than 20 ohms

7. A 10-ohm resistor has a 5-A current in it. What is the voltage across the resistor?

5 V

10 V

15 V

20 V

More than 20 V

8. Heat a copper wire and its electric resistance

Decreases

Remains uncharged

Increases

9. Electrons move in an electrical circuit

By being bumped by other electrons

By colliding with molecules

By interacting with an established electric field

Because the wires are so thin

None of these

10. In an electric circuit, the safety fuse is connected to the circuit in

Series

Parallel

11. When two lamps are connected in series to a battery, the electrical resistance that the battery senses is

More than the resistance of either lamp

Less than the resistance of either lap

None of these

12. Electrons are made to flow in a wire when there is

An imbalance of charges in the wire

More potential energy at one end of the wire than the other

A potential difference across its ends

13. On some early automobiles both headlights went out when one bulb burned out. The headlights must have been connected in

Parallel

Perpendicular

Series

Haste

14. Which is more dangerous, touching a faulty 110-volt light fixture, or a van de graaff generator charged to 100,00 volts?

Touching the light fixture

Touching the generator

Touching both are about equally dangerous

15. In an ac circuit, the electric field

Increases via the inverse square law

Changes magnitude and direction with time

Is everywhere the same

Is non-existent

None of these

16. When a light switch is turned on in a dc circuit, the average speed of electrons in the lamp is

The speed of sound waves in metal

The speed of light

1000 cm/s

Less than 1 cm/s

Dependent on how quickly each electron bumps into the next electron

17. As more lamps are put into a parallel circuit, the overall current in the power source

Increases

Decreases

Stays the same

18. Compared to a single lamp connected to a battery, two lamps connected in parallel to the same battery will carry

More current

Less current

The same current

19. Which statement is correct?

Charge flows in a circuit

Voltage flows through a circuit

Resistance is established across a circuit

Current causes voltage

20. An electrical diode is useful for

Storing electrical energy

Boosting voltage

Limiting current

Voltage modification

Changing ac to dc

21. Compared to the filament thickness of a 60-W light bulb, the filament of a 100-W light bulb will be

Thinner

Thicker

The same

22. A 60 W light bulb and a 100- W light bulb are each connected to a 120 V outlet. Which light bulb has more current in it?

The 60- W bulb

The 100- W bulb

Both have the same current

23. When two lamps are connected in parallel to a battery, the electrical resistance that the battery senses is

More than the resistance of either lamp

Less than the resistance of either lamp

None of these

24. A 100-watt lamp glows brighter than a 25-Watt lamp. The electrical resistance of the 100-watt lamp must be

Less

Greater

The same

25. a circuit breaker serves the same purpose as

A switch

A fuse

A capacitor

A battery

None of these

26. In a common dc circuit, electrons move at speeds of

A fraction of a centimeter per second

Many centimeters per second

The speed of a sound wave

The speed of light

None of these

27. As more lamps are put into a series circuit, the overall current in the power source

Increases

Decreases

Stays the same

28. The electric power of a lamp that carries 2 A at 120 V is

1/6 watts

2 watts

60 watts

20 watts

240 watts

29. The source of electrons lighting an incandescent as light bulb is

The power company

Electrical outlet

Atoms in the light bulb filament

The wire leading to the lamp

The source voltage

30. Compared to the resistance of two resistors connected in series, the same two resistors connected in parallel have

More resistance

Less resistance

The same resistance

31. A 60- W light bulb and a 100-W light bulb are each rated at 120 V. which light bulb has a larger resistance?

The 60- W bulb

The 100- W bulb

Both have the same resistance

32. Stretch a copper wire so that it is thinner and the resistance between its ends

Decreases

Remains unchanged

Increases

33. A woman experiences an electrical shock. The electrons making the shock come from the

Woman's body

Ground

Power plant

Hairdryer

Electric field in the air

34. The number of electrons delivered daily to an average American home by an average power utility in the mid 1980s was

Zero

110

220

Billion of billions

None of these

35. The power dissipated in a 4-ohm resistor carrying 3 A is

7 W

18 W

36 W

48 W

Not enough information to say

36. A heater uses 20 A when used in a 110-V line. If electric power costs 10 cents per kilowatt hour, the cost of running the heater for 10 hours is

$0.22

$0.55

$2.20

$5.50

None of these

37. A coulomb of charge that passes through a 6-volt battery is given

6 joules

6 amperes

6 ohms

6 watts

6 newtons

38. A 4-ohm resistor is connected in parallel with a 6-ohm resistor. this combination produces an equivalent resistance of

2.4 ohms

4 ohms

5 ohms

5.5 ohms

10 ohms

39. Compared to the amount of electric current in the filament of a lamp, the amount of current in the connecting wire is

Definitely less

Often less

Actually more

The same

Incredibly all of these

40. Alternating current is normally produced by a

Battery

Generator

Both of these

Neither of these

41. A wire that carries an electric current

Is electrically charged

May be electrically charged

Is never electrically charged

42. Two lamps, one with thick filament and one with a thin filament of the same material, are connected in parallel to a battery. the current is larger in the lamp with the

Thick filament

Thin filament

Current is the same in both

43. The source of electrons in an ordinary electrical circuit is

A dry cell, wet cell or battery

The back emf of motors

The power station generator

The electrical conductor itself

None of these

44. Two lamps, one with a thick filament and one with a thin filament, are connected in parallel to a battery. the voltage is greatest across the lamp with the

Thick filament

Thin filament

Both voltages are the same

45. Connect a pair of lamps in series and you draw current from the connected battery. connect the same lamps in parallel and you draw

The same current

More current

Less current

Sometimes more, sometimes less

46. A 60-watt light bulb is connected to a 120-volt plug. what is the current in the light bulb?

0.25 A

0.5 A

2 A

4 A

More than 4 A

47. Compared to a single lamp connected to a battery, two identical lamps connected in series to the same batter will carry

More current

Less current

The same current

48. A circuit is powered with a battery. charge flows

Out of the battery and into the circuit

From the negative battery terminal to the positive terminal

After a couple seconds passes

Through both the battery and the rest of the circuit

None of these

49. If you plug an electric toaster rated at 110 V into a 220-V outlet, the current in the toaster wil be about

Half what it should be

The same as if it were plugged in 110 V

More than twice what it should be

Twice what it should be

50. In the circuit of figure 23-A, energy is given to the moving charges by

The bulb

The wires

A generator which is not shown

Non of these

51. A capacitor is used to store

Charge

Energy

Both

Neither

52. Two lamps, one with a thick filament and one with a thin filament of the same material, are connected in series to a battery. the voltage is greater across the lamp with the

Thick filament

Thin filament

Voltage is the same for both

53. There are electrons int he filament of the ac lamp in your bedroom. When you turn on the lamp and it glows, the glowing comes from

Different electrons; the ones that flow in the circuit to your lamp

The same electrons

The positive charges that flow in the filament

54. The current through two identical light bulbs connected in series is 0.25 A. the voltage across both bulbs is 110 V. the resistance of a single light bulb is

22 ohms

44 ohms

220 ohms

440 ohms

None of these

55. A power line with a resistance of 2 ohms has a current of 80 A in it. the power dissipated in the line is

40 W

160 W

320 W

12800 W

None of these

56. When we say an appliance "uses up electricity," we really are saying that

Current disappears

Electric charges are dissipated

The main power supply voltage is lowered

Electrons are taken out of the circuit and put somewhere else

Electron kinetic energy is changed into heat

57. When a pair of 1-ohm resistors are connected in series, their combined resistance is

1 ohm, and when connected in parallel, 2 ohms

2 ohms, and when in parallel 1 ohm

1/2 ohm, and when in parallel, 2 ohms

2 ohms, and when in parallel 1/2 ohm

Non of these

58. A capacitor is useful in

Boosting the energy output of a circuit

Increasing the current in a resistor

Smoothing pulsed current

Switching dc to ac in a circuit

Increasing or decreasing voltage

59. A wire carrying a current is normally charged

Negatively

Positively

Not at all

60. Two lamps, one with a thick filament and one with a thin filament, are connected in series. The current is greater in the lamp with the

Thick filament

Thin filament

The same in each lamp

61. An electric hater is rated at 300 W when used in a 110-V circuit. The safety fuse n the circuit can handle 15 A of current. how many heaters can be safely operated in the circuit?

2

3

4

5

More than 5

62. In the 110-volt circuit shown,

110 coulombs of charge flow through the lamp every second

110 joules of energy are converted to heat and light in the circuit every second

110 joules of energy are given up by each coulomb of charge making up the current in the circuit

110 joules of energy are shared among all the coulombs in the circuit at any instant

None of the above

63. What is the resistance of a 120-W incandescent lamp connected to a 120-V power supply?

1 ohm

60 ohms

100 ohms

144 ohms

None of these