True/False (Value 5) Indicate
whether the statement is true or false.
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1.
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The cables used to transfer electric energy from the generating station to the
consumers must be of low resistance to reduce losses due to joule heating.
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2.
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Electric energy is transferred from generating stations to consumers’
premises at extremely low voltage.
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3.
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A resistor is a device that controls current in electric circuits.
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4.
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A resistor is a device that converts chemical energy into electric
energy.
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5.
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An ampere is a unit used by electric companies to measure electrical energy
use.
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Multiple Choice (Value 10) Identify the choice that best completes the statement or answers
the question.
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6.
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Which of the following circuits can be used to test whether or not a wire of a
laminated heating element is cut internally?
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7.
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A/An _____ is described as the flow of positive charges that move from a higher
to lower potential energy.
a. | electron flow | c. | electric circuit | b. | conventional current | d. | conventional
circuit |
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8.
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_____ is described as a property that determines how much current will flow for
a given battery voltage.
a. | Resistance | c. | Kilowatt-hour | b. | Resistor | d. | Thermal energy |
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9.
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_____ is a property that determines how much current will flow for a given
source voltage, whereas a _____ is a device that controls the current in a circuit.
a. | Resistance, resistor | c. | Resistor, resistance | b. | Resistance, battery | d. | Battery,
resistance |
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10.
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A sensor uses 2.0 10 -4 A of current when it is
operated by a 3.0 V battery. What is the resistance of the sensor circuit?
a. | 6.7 10-5 ohms | c. | 1.5
104 ohms | b. | 6.0 10-4
ohms | d. | 6.9 104 ohms |
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11.
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A/An _____ is described as a closed loop or pathway that allows electric charges
to flow.
a. | electric circuit | c. | parallel connection | b. | conventional current | d. | series
connection |
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12.
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A lamp uses 15 W of power when it is connected across 25 V. What is the
current through the lamp?
a. | 0.60 A | c. | 9.38 103 A | b. | 1.67
A | d. | 93.8
103 A |
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13.
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A car battery causes a current of 2.0 A through a lamp and produces 12 V across
it. What is the power used by the lamp?
a. | 0.167 W | c. | 24 W | b. | 6 W | d. | 48 W |
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14.
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The current through a lightbulb connected across the terminals of a 125 V outlet
is 0.50 A. Assuming 100% efficiency, at what rate does the bulb convert electric energy to
light?
a. | 0.004 W | c. | 63 W | b. | 25 W | d. | 250 W |
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15.
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A/An _____ is described as the flow of electric charge or current equal to one
coulomb per second.
a. | volt | c. | capacitance | b. | capacitor | d. | ampere |
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Matching (Value 4)
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Define the following terms by matching them with the correct
definition. a. | electric current | e. | resistance | b. | conventional
current | f. | resistor | c. | battery | g. | ampere | d. | electric
circuit | h. | kilowatt-hour |
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16.
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a flow of charged particles
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17.
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an energy unit used by electric companies to measure energy use
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18.
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a device with specific resistance; used to control current in circuits
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19.
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a device that converts chemical energy to electric energy
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Problem (Value 24)
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20.
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There is a 0.40-A current in resistor X when it is connected to a 2.0-V battery.
A 0.25-A current is in a second resistor, Y, when it is connected to a 4-V battery. There is a 0.50-A
current in a third resistor, Z, when it is connected to a 5.0-V battery. Find the resistor that has
the maximum resistance and the resistor that has the least resistance.
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21.
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How much energy is consumed in 10 minutes by a bulb with a resistance of 50
W when connected to a 50-V battery?
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22.
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The table below shows a list of some electric appliances with the values of
their potential differences and current. Which appliance consumes the most power? Appliance | Potential difference (V) | Current (A) | Television | 24 | 0.75 | Drill | 110 | 1.6 | Bulb | 12 | 4.0 | Amplifier | 110 | 0.2 | | | |
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23.
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Bulb P is rated 60 W, 110 V and bulb Q is rated 100 W, 110 V. Which of the bulbs
has the higher resistance?
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24.
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An electric iron dissipates 1.5 kW when connected to a 110-V supply. By what
factor should the resistance of its heating element be changed so that it consumes only 1 kW?
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25.
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A hair dryer rated at 1.5 kW, 110 V is used for 4 minutes every day for one
month. Calculate the energy delivered to the hair dryer in one month in kilowatt-hours.
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26.
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How many kilowatt-hours of energy does an appliance rated as W
and 1.10 10 2 V consume in 15.0
minutes?
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27.
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The table below shows a list of some electric appliances with their power
ratings and the duration for which they are used in Jody’s house over one month. Which
appliance consumed the maximum total energy and how many kilowatt-hours were consumed? Appliance | Power rating (W) | Duration of use (hours) | Television | 100 | 60 | Drill | 1000 | 1 | Bulb | 60 | 150 | Amplifier | 120 | 60 | | | |
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