True/False
Indicate whether the statement is
true or false.
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1.
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 If the measured power is smaller than the reference
power, the dB calculated will be a positive number and indicate a measurement of loss.
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2.
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 If the measured power is larger than the reference
power, the dB calculated will be a positive number and indicate a measurement of gain.
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3.
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International standards and some US standards that have adopted them calculate
loss or attenuation as a positive number and gain as negative number, different from other
definitions of dB.
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Multiple Choice
Identify the choice that best
completes the statement or answers the question.
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4.
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The “dB” or “decibel” was named for _________.
a. | The Liberty Bell | b. | Alexander Graham Bell | c. | Belle
Star | d. | The Bell Curve |
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5.
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 In the equation defining dB, power is measured in units
of ________. a. | Watts, milliwatts or microwatts | b. | dB | c. | dBm | d. | Newtons |
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6.
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 If the dB equation is used for defining dBm,
________. a. | The measured power must be in milliwatts | b. | The reference power
is 1 milliwatt | c. | The reference power can be any power from +20 to -30 dBm | d. | Both measurements
must be in dB |
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7.
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 If the measured power is twice the reference power, the
dB equation will calculate the dB change as , ________. a. | -3dB | b. | -2 dB | c. | 0
dB | d. | +3dB |
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8.
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 If the measured power is equal to the reference power,
the dB equation will calculate the dB as , ________. a. | -3dB | b. | -2 dB | c. | 0
dB | d. | +3dB |
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9.
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 If the measured power is half the reference power, the
dB equation will calculate the dB change as , ________. a. | -3dB | b. | -2 dB | c. | 0
dB | d. | +3dB |
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10.
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The difference between dB and dBm is ___________.
a. | dB measures power while dBm measures gain or loss | b. | dBm measures power
while dB measures gain or loss |
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11.
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If you are measuring the output of a fiber optic transmitter, you make the
measurement in _________.
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12.
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If you are measuring the input of a fiber optic receiver, you make the
measurement in _________.
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13.
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If you are measuring the loss of a fiber optic cable, you make the measurement
in _________.
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14.
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OTDRs and OLTS measure loss as a positive number and gain as a negative number
because ____________.
a. | Both mresure the loss first then the reference | b. | They follow an
international standard that changed the dB equation | c. | Both measure using backscatter which changes
the ratio of power | d. | Their display cannot show negative
numbers |
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