Multiple Choice Identify the choice that best completes the
statement or answers the question.
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1
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When a 15-V battery is connected to a resistor, 2 A of current flows in the
resistor. What is the resistor's value?
a. | 30 ohms | b. | 2 ohms | c. | 7.5 ohms
| d. | 15 ohms | e. | more than 30
ohms |
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2
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A light bulb is plugged into a 120-volt outlet and has a 0.3 A current in it.
What is the power rating of the light bulb?
a. | 120 W | b. | 40 W | c. | 400
W | d. | 36 W | e. | 12 W |
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3
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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 |
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4
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The frequency of AC current in North America is
a. | 60 hertz. | b. | 50 hertz. | c. | 30
V. | d. | 120 V. |
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5
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Current from a battery is always
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6
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What is the SI unit for electrical potential energy?
a. | volts | b. | coulombs | c. | watts | d. | joules |
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7
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Electric power is defined as
a. | current times resistance. | b. | resistance times voltage. | c. | current times
voltage. | d. | voltage divided by current. | e. | current divided by
voltage. |
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8
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What affect would tripling the resistance in
a circuit have on the current.
a. | decrease it by a factor of six | c. | increase it by a factor of three | b. | decrease it by a factor of three | d. | increase it by a
factor of six |
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9
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How much power is used by a 6.0-V flashlight battery that draws 1.5 A of
current?
a. | 30 W | b. | 6 W | c. | 4
W | d. | 1.5 W | e. | 9 W |
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10
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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 |
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11
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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?
a. | the 100-W bulb. | b. | The same amount of current flows in
both. | c. | the 60-W bulb. |
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12
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Any path along which electrons can flow is called a
__________.
a. | potentiometer | c. | electrical pathway | b. | electrical
circuit | d. | wire |
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13
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Electric potential is defined as
a. | electrical potential energy. | b. | electrical potential energy of a charge divided
by the quantity of the charge. | c. | voltage. | d. | electrical potential
energy of a charge multiplied by the quantity of the charge. | e. | gravitational
potential. |
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14
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If you plug an electric toaster rated at 110 V into a 220-V outlet, current in
the toaster will be
a. | the same as if it were plugged into 110 V. | b. | more than twice what
it should be. | c. | twice what it should be. | d. | half what it should be. | e. | none of the
above |
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15
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An ampere is a
a. | unit of current. | b. | current. | c. | type of
charge. | d. | voltage. | e. | unit of
resistance. |
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16
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While you are standing on the ground in your running shoes, the greatest
resistance between you and the ground is in
a. | the running shoes. | b. | the clothes you are
wearing. | c. | your skin. | d. | your muscles. | e. | your
legs. |
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17
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When connected to a 110-volt power supply, how much current is in a light bulb
that has a resistance of 330 ohms?
a. | 330 A | b. | 0.3 A | c. | 110
A | d. | 36,300 A | e. | 3.0 A |
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18
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Power outlets in our homes typically have a potential difference of
a. | 240 V. | b. | 120 A. | c. | 30
V. | d. | 60 A. | e. | 120 V. |
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19
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For most conductors, as their temperature increases, their resistance
a. | increases. | b. | decreases. | c. | stays the
same. |
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20
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A 10-ohm resistor has a 3-A current in it. What is the voltage across the
resistor?
a. | 3 V | b. | 18 V | c. | 13
V | d. | 10 V | e. | more than 18 V |
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21
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A 20-ohm resistor has a 5-A current in it. What is the voltage across the
resistor?
a. | 5 V | b. | 20 V | c. | 30
V | d. | 25 V | e. | more than 30 V |
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22
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The current through a 5-ohm resistor connected to a 150-V power supply is
a. | 10 A. | b. | 30 A. | c. | 150
A. | d. | 1A. | e. | none of the
above |
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23
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When a 10-V battery is connected to a resistor, 2 A of current flows in the
resistor. What is the resistor's value?
a. | 20 ohms | b. | 5 ohms | c. | 2 ohms
| d. | 10 ohms | e. | more than 20
ohms |
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24
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Touching a charged body to earth to eliminate
excess charge is called __________.
a. | charging | c. | equalizing | b. | grounding | d. | static
equilibrium |
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25
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In circuits of metal wires, _____________ are the
flowing charged particles.
a. | electrons | c. | neutrons | b. | protons | d. | protons or
electrons |
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26
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What affect would tripling the voltage in a
circuit have on the current.
a. | decrease it by a third | c. | triple it | b. | increase it by a
factor of 6 | d. | no effect |
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27
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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. | 4 ohms | b. | 8 ohms | c. | 2 ohms
| d. | 16 ohms | e. | more than 16
ohms |
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28
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Electrical resistance in a wire depends on the wire's
a. | thickness. | b. | length. | c. | conductivity. | d. | all of the above | e. | none of the
above |
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29
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Compared to thin wires, electrical resistance in thick wires is
a. | less. | b. | the same. | c. | greater. |
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30
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When plugged into a 120-V wall outlet, how much current is used by a lightbulb
rated at 100 W?
a. | 100 A | b. | 0.8 A | c. | 12,000
A | d. | 120 A | e. | none of the
above |
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31
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If you accidentally grabbed the prongs of a partially plugged-in 120-V
electrical plug on a day when your skin resistance was 140,000 ohms, how much current would pass
through your body?
a. | 1,167 A | b. | 16,800,000 A | c. | 140,000
A | d. | 120 A | e. | 0.0009 A |
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32
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Materials through which charges do
not move easily. (e.g. glass, dry wood, most plastics, cloth, and dry air) are called
_____________.
a. | insulators | c. | ionic
compounds | b. | circuits | d. | conductors |
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33
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Electrical resistance is measured in
a. | watts. | b. | amperes. | c. | joules. | d. | volts. | e. | none of the
above |
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34
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In solid conductors, electric current is the flow of
a. | protons. | b. | negative ions. | c. | positive and
negative charges. | d. | electrons. | e. | none of the
above |
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35
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An example of a voltage source is
a. | a car battery. | b. | a generator. | c. | a dry
cell. | d. | rubbing a rubber rod with fur. | e. | all of the
above |
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36
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Materials that allow charges to move about easily
(e.g. metals, plasma (ionized gas), graphite) are called _____________.
a. | circuits | c. | conductors | b. | insulators | d. | ionic compounds |
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37
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What is the SI unit for charge?
a. | volt | b. | watt | c. | coulomb | d. | joule |
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38
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The rate at which energy is
transferred is called ____________.
a. | work | c. | energy | b. | current | d. | power |
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39
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What is the resistance of a toaster that uses 3 A of current when connected to a
120-volt power source?
a. | 360 ohms | b. | 120 ohms | c. | 40
ohms | d. | 3 ohms | e. | none of the
above |
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40
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A volt is a unit of
a. | charge. | b. | current. | c. | electric
potential. | d. | work. | e. | energy. |
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