Prefixes for unit of electrical measurement
In electronics we are often dealing with units that are very large or very small, thus we rely on exponents for formal expression.
| Prefix | Symbol | Expression as exponent | Expression as decimal value | English word |
|---|---|---|---|---|
| Terra- | T | \(10^{12}\) | 1,000,000,000,000 | trillion |
| Giga- | G | \(10^9\) | 1,000,000,000 | billion |
| Mega- | M | \(10^6\) | 1,000,000 | million |
| Kilo- | k | \(10^3\) | 1,000 | thousand |
| Centi- | c | \(10^{-2}\) | 0.01 | hundredth |
| Milli- | m | \(10^{-3}\) | 0.001 | thousandth |
| Micro- | \(\mu\) | \(10^{-6}\) | 0.0000001 | millionth |
| Nano- | n | \(10^{-9}\) | 0.0000000001 | billionth |
| Pico- | p | \(10^{-12}\) | 0.0000000000001 | trillionth |
For example, with Amps we tend not to use 1 whole amp as this is far too large for most electronics. More common is the milliampere (mA) and the microampere (\(\mu\)A).
A mA is equal to one thousandth of an ampere: 0.001 A. It takes 1000 milliamperes to equal one ampere.
A \(\mu\)A is equal to one millionth of an ampere: 0.0000001 A. It takes one million micoramperes to equal one ampere.
