Several of the exam
questions involve converting metric units from one form to another. By
memorizing what a few unit prefixes mean, these questions become easy.
Look at the table below:
Prefix

Size

Multiply/Divide by

pico

one millionth of a
millionth

.0000000000001 or
1E12

micro

one millionth

.000001

milli

one thousandth

.001

kilo

one thousand

1000

mega

one million

1,000,000

giga

one billion

1,000,000,000

 a kilohertz is one thousand hertz
 a megahertz is one million hertz
 a milliampere is one one thousandth of an ampere
 a microvolt is one one millionth of a volt
From

To

Multiply/Divide By

Mega

Kilo

x1000

Kilo

Mega

/1000

One

milli

x1000

milli

One

/1000

milli

micro

x1000

One

micro

/1,000,000

pico

micro

/1,000,000

mega

One

x1,000,000

The prefix in front of a
unit just tells you how many of those units your talking about. A few
examples:
To convert between
prefixes, there are two steps you can follow. First, convert the original
unit to single units, (megahertz to hertz for example), then convert the single
units to the second prefix, (hertz to kilohertz for example). To convert
from a bigger unit, (megahertz for example), to a smaller unit, (hertz),
multiply the number of the bigger units by the number in the right hand column
above for the prefix, so 3.525 megahertz, (MHz), is 3.525 x 1,000,000 =
3,525,000 Hertz, (Hz). To convert from a smaller unit to a larger unit,
divide by the number in the right hand column, so 3,525,000 hertz / 1000 = 3525
kilohertz.
Rules of Thumb
Sometimes it’s simpler
to remember a few rules of thumb in the next table. These will become
more familiar to you the more you use them for actual radio operations.
Exam Questions:
186T5B01CHow many
milliamperes is 1.5 amperes?
A. 15 milliamperes
B. 150 milliamperes
C. 1,500 milliamperes
D. 15,000 milliamperes
187T5B02AWhat is
another way to specify a radio signal frequency of 1,500,000 hertz?
A. 1500 kHz
B.
1500 MHz
C.
15 GHz
D.
150 kHz
188T5B03CHow many
volts are equal to one kilovolt?
A. One onethousandth of
a volt
B. One hundred volts
C. One thousand volts
D. One million volts
189T5B04AHow many
volts are equal to one microvolt?
A. One onemillionth of a volt
B. One million volts
C. One thousand
kilovolts
D. One onethousandth of
a volt
190T5B05BWhich of
the following is equivalent to 500 milliwatts?
A. 0.02 watts
B. 0.5 watts
C. 5 watts
D. 50 watts
191T5B06CIf an
ammeter calibrated in amperes is used to measure a 3000milliampere current,
what reading would it show?
A. 0.003 amperes
B. 0.3 amperes
C. 3 amperes
D. 3,000,000 amperes
192T5B07CIf a
frequency readout calibrated in megahertz shows a reading of 3.525 MHz, what
would it show if it were calibrated in kilohertz?
A.
0.003525 kHz
B.
35.25 kHz
C. 3525 kHz
D.
3,525,000 kHz
193T5B08BHow many
microfarads are 1,000,000 picofarads?
A. 0.001 microfarads
B. 1 microfarad
C. 1000 microfarads
D. 1,000,000,000
microfarads
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