|
Prefix |
Symbol |
10n |
US English Term |
Decimal |
Adoption |
| quetta | Q | 1030 | nonillon | 1 000 000 000 000 000 000 000 000 000 000 | 2022 |
| ronna | R | 1027 | octillion | 1 000 000 000 000 000 000 000 000 000 | 2022 |
|
yotta |
Y |
1024 |
septillion |
1 000 000 000 000 000 000 000 000 |
1991 |
|
zetta |
Z |
1021 |
sextillion |
1 000 000 000 000 000 000 000 |
1991 |
|
exa |
E |
1018 |
quintillion |
1 000 000 000 000 000 000 |
1975 |
|
peta |
P |
1015 |
quadrillion |
1 000 000 000 000 000 |
1975 |
|
tera |
T |
1012 |
trillion |
1 000 000 000 000 |
1960 |
|
giga |
G |
109 |
billion |
1 000 000 000 |
1960 |
|
mega |
M |
106 |
million |
1000 000 |
1960 |
|
kilo |
k |
103 |
thousand |
1 000 |
1795 |
|
*hecto |
h |
102 |
hundred |
100 |
1795 |
|
*deca |
da |
101 |
ten |
10 |
1795 |
|
(unity) |
(none) |
100 |
one |
1 |
ancient |
|
*deci |
d |
10−1 |
tenth |
0.1 |
1795 |
|
*centi |
c |
10−2 |
hundredth |
0.01 |
1795 |
|
milli |
m |
10−3 |
thousandth |
0.001 |
1795 |
|
micro |
µ |
10−6 |
millionth |
0.000 001 |
1960 |
|
nano |
n |
10−9 |
billionth |
0.000 000 001 |
1960 |
|
pico |
p |
10−12 |
trillionth |
0.000 000 000 001 |
1960 |
|
femto |
f |
10−15 |
quadrillionth |
0.000 000 000 000 001 |
1964 |
|
atto |
a |
10−18 |
quintillionth |
0.000 000 000 000 000 001 |
1964 |
|
zepto |
z |
10−21 |
sextillionth |
0.000 000 000 000 000 000 001 |
1991 |
|
yocto |
y |
10−24 |
septillionth |
0.000 000 000 000 000 000 000 001 |
1991 |
| ronto | r | 10−27 | octillionth | 0.000 000 000 000 000 000 000 000 001 | 2022 |
| quecto | q | 10−30 | nonillionth | 0.000 000 000 000 000 000 000 000 000 001 | 2022 |
*Note: Not based 1000x intervals.
Also see this web page for more examples.
Metric Units Examples
|
Prefix |
Symbol |
10n |
US English Term |
Length |
| quetta | Q | 1030 | nonillion |
Jupiter weights ~2 Qg (gram) Formally 1 Gegobyte |
| ronna | R | 1027 | octillion |
Earth weights ~6 Rg (gram) |
|
yotta |
Y |
1024 |
septillion |
Yottabyte = 1,208,925,819,614,629,174,706,176 bytes Visible universe: 43 Ym Hubble sphere radius = 14.4 billion light years where galaxies move away from Earth at the speed of light: 136 Ym |
|
zetta |
Z |
1021 |
sextillion |
Our Milky Way Galaxy: 1 Zm |
|
exa |
E |
1018 |
quintillion |
Distance to nearest stars: 1 Em |
|
peta |
P |
1015 |
quadrillion |
Light year 9.46 Pm
Age if the universe 500 Ps |
|
tera |
T |
1012 |
trillion |
Across the orbits of the outer planets 10 Tm |
|
giga |
G |
109 |
billion |
Distance to the sun 150 Gm |
|
mega |
M |
106 |
million |
Earth to Moon 384 Mm; Diameter of Earth 12.7 Mm; Circumference of the Earth 40 Mn; Distance across USA 3.93 Mm |
|
kilo |
k |
103 |
thousand |
Mt. Everest above sea level 8.85 km; Marathon 42 km |
|
*hecto |
h |
102 |
hundred |
Sprint track race 100 m |
|
*deca |
da |
101 |
ten |
City block about 80 m; Football field 91.7 m; Oak tree 10 m |
|
(unity) |
(none) |
100 |
one |
Man 1.8 m |
|
*deci |
d |
10−1 |
tenth |
Hand 1 |
|
*centi |
c |
10−2 |
hundredth |
Finger nail, dime about 1 cm or 100 mm |
|
milli |
m |
10−3 |
thousandth |
Tip of a pencil 1 mm |
|
micro |
µ, mc |
10−6 |
millionth |
White blood cell 100 µm. Also written as mc (medical). E.g. mcg (microgram) |
|
nano |
n |
10−9 |
billionth |
DNA 2.5 nm |
|
pico |
p |
10−12 |
trillionth |
Atoms 62 to 520 pm |
|
femto |
f |
10−15 |
quadrillionth |
Proton 1 fm |
|
atto |
a |
10−18 |
quintillionth |
Quark 100 am; Unknown < 10 am |
|
zepto |
z |
10−21 |
sextillionth |
Unknown |
|
yocto |
y |
10−24 |
septillionth |
Unknown |
| ronto | r | 10−27 | octillionth | |
| quecto | q | 10−30 | nonillionth | Weight of an electron ~1qg (gram) |
Computer Prefixes
Computers are built around binary numbers. Binary numbers 1, 2, 4, and 8 are written as 1, 10, 100 and 1000. In binary there are just two symbols used 0 and 1. Every time you add another digit to the left of a binary number, you double the number.
We commonly use decimal notation which means very time you add another digit to the left of a binary number you multiply it by ten.
When a computer is built, it is built around binary numbers. The number 1024 when written in binary is 1000000000. You can see that binary numbers are awkward to write. Since 1024 is about 1000, the people started to call 1024 a "K". It is pretty close. This is how much a kilobyte really is.
The next symbol was "M" and this was 1024 times 1024 which as pretty close to a million. It actually is 1,049,576. This is how much a megabyte really is.
As things got bigger, a "G" symbol was added. This was 1024 times 1024 times 1024 or about a billion. But not exactly. It really was 1,073,741,824. This is actually how much a gigabyte is.
|
Prefix |
Symbol |
2n |
Number of Bits |
Spelled Out |
| Bit | -- | 0 | 1 | 1 bit |
| Byte | B | 3 | 8 | 8 bits |
| Kilo | KB | 10 | 1 024 | 1024 bits |
| Mega | MB | 20 | 1 048 576 | 1024 Kilobytes |
| Giga | GB | 30 | 1 073 741 824 | 1024 Megabytes |
| Tera | TB | 40 | 1 099 511 627 776 | 1024Gigabytes |
| Peta | PB | 50 | 1 125 899 906 842 624 | 1024 Terabytes |
| Exa | EB | 60 | 1 152 921 504 606 846 976 | 1024 Petabytes |
Electromagnetic Spectrum
|
Item |
Wavelength |
|
Frequency |
|
|
Gamma radiation |
< 10 pm |
> 10 EHz |
||
| X Rays |
10 pm - 10 nm |
30 PHz - 30 EHz |
||
| Vacuum Ultraviolet | 40 -190 nm | 1.57 - 7.5 PHz | extreme > 100 nm | |
| Ultraviolet UVC |
220 -290 nm |
1.07 PHz - 3.0 PHz | far 190 - 220 nm germicidal totally absorb by atmosphere | |
| Ultraviolet UVB | 290 - 320 nm | 952 THz - 1.07 PHz | middle 200 - 300 nm destructive sunburn | |
| Ultraviolet UVA | 320 - 400 nm | 315 - 750 THz | near 300 -400 nm tanning | |
| Violet |
400 - 424 nm |
707 - 750 THz | Ref: Physics Hypertextbook | |
| Blue |
424 - 491 nm |
610 - 707 THz |
||
| Green |
491 - 575 nm |
521 - 610 THz |
||
| Yellow |
575 - 585 nm |
512 - 521 THz |
||
| Orange |
585 - 647 nm |
463 - 512 THz |
||
| Red |
647 - 700 nm |
428 - 463 THz |
||
| Near Infrared |
750 nm –1.4 µm |
214 - 400 THz |
Defined by the water absorption, and commonly used in fiber optics, night vision goggles, TV clickers. Most cellphone cameras can see into this spectrum. |
|
| Short Wave Infrared |
1.4-3 µm |
214 - 100 THz |
Water absorption occurs band 1.45 µm. Fiber optics band 1.53 to 1.560 µm |
|
| Mid Wave Infrared |
3–8 µm |
100 - 37.4 THz |
Atmospheric window used for heat seeking guided missile 3–5 µm |
|
| Long Wave Infrared |
8–15 µm |
19.9 - 37.4 THz |
Thermal Infrared Region. Objects give off this type of radiation as a function of temperature. Forward-looking infrared (FLIR) cameras use this part of the spectrum. |
|
| Far Infrared |
15–1,000 µm |
3.00 - 19.7 THz |
Cool objects (5 K and 340 K) radiation. Used to observe interstellar gases such as M82. |
|
| Microwave Submillimeter |
100 µm - 1 mm |
300 GHz - 3000 GHz |
||
| Extreme EHF | 1 - 10 mm | 30 - 300 GHz | ||
| Super SHF microwave | 10 -100 mm | 3 - 30 GHz | ||
| Ultra High Freq. UHF | 100 mm - 1 m | 300 MHz - 3 GHz | Microwave Oven 122 mm, 2.45 GHz | |
|
Very High Freq. VHF |
1 - 10 m | 30 - 300 MHz | Microwave low end 1 m, 300 MHz | |
|
High Freq. HF |
10 - 100 m | 3 - 30 MHz | ||
| Medium MF | 100 km - 1 Mm | 300 kHz - 3 MHz | ||
| Low Freq. LF | 1 - 10 km | 30 - 300 kHz | ||
| Very Low Freq. VLF | 10 -100 km | 3 - 30 kHz | ||
| Extreme Low Freq. ELF | 100 - 3 Mm | 100 Hz - 3 KHz | ||
| Ultra Low Freq. ULF | > 3 Mm | <100 Hz | ||
| 2 Meter Ham Band | 2 m | 149 MHz | ||
| TV Channel 2 USA | 5.55 m | 54 MHz | ||
|
TV Channel 6 USA |
3.65 m | 82 MHz | ||
|
TV Channel 7 USA |
1.72 m | 174 MHz | ||
|
TV Channel 13 USA |
1.42 m | 210 MHz | ||
|
TV Channel 14 USA |
0.63 m | 470 MHz | ||
|
TV Channel 83 USA |
0.34 m | 884 MHz | ||
| FM Radio USA | 2.77 - 3.41 m | 88 - 108 MHz | ||
| Short Wave HF | 9.99 - 176 m | 1.7 - 30 MHz | ||
| AM Broadcast Band (USA) | 176 - 555 m | 540 - 1.7 MHz | ||
| WWVB | 5.00 km | 60 KHz | ||
| AC Current | 5.00 Mm | 60 Hz | Wave length is 3,090 Miles |
Capacitor Conversion Values
|
Power of Ten |
Microfarads |
Nanofarads |
Picofards |
| -6 | 1 uf | 1 000 nf | 1 000 000 pf |
| -7 | .1 uf | 100 nf | 100 000pf |
| -8 | .01 uf | 10 nf | 10 000pf |
| -9 | .001 uf | 1 nf | 1000 pf |
| -10 | .0 001 uf | .1 nf | 100 pf |
| -11 | .00 001 uf | .01 nf | 10 pf |
| -12 | .000 0001 uf | .001 nf | 1 pf |
Thus 21010^(-9) f = 1 nf = .001 uf = 1000 pf.
WAVELENGHT and FREQUENCY CONVERSION
c = f * w
w = c/f
f= c/w
where: w = wavelength in meters, f = frequency in Hz
c =velocity of light in a vacuum = 299,792,458 m/s
_____________________
For f in MHz
f = 300/w approximation
w = 300/f approximation
_____________________
Dipole length Antenna Formulas (f is in MHz)
Antenna length in meters = 150/f
Antenna length in inches = 5905/f
Antenna length in feet = 492/f
In actual practice, the end effect should be considered. The result from the above formula should be multiplied by about 0.95.
Antenna length in meters = 142.5/f
Antenna length in inches = 5609.75/f
Antenna length in feet = 467.4/f
If a quarter length antenna is being considered with an end effect included:
Antenna length in meters = 71.25/f
Antenna length in inches = 2,804.875/f
Antenna length in feet = 233.7/f
Radio Bands (VLF, LF, MF, HF, VHF, UHF, SHF, EHF) Allocations
George Norwood
KE5KDO
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