SI Units
Basic Concepts
- SI units stands for International System of unit (Système International). It is metric unit system that is used universally as a standard for measurements.
- Fundamental quantities are those quantities that are considered to be so basic that all other quantities need to be expressed in terms of them.
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Meter (m): the length of the path travelled by light in a vacuum during a time interval of 1/273.16 of a second.
Introductory Lecture About SI Units
Notes For SI Units
SI Base Units
SI Units Prefix
| Quantity | Unit | Symbol |
|---|---|---|
| Length | Meter | m |
| Mass | Kilogram | kg |
| Time | Second | s |
| Temperature | Kelvin | °K |
| Amount of substance | Mole | mol |
| Current | Ampere | A |
| Luminous intensity | Candela | cd |
| Plane angle | Radian | rad |
| Solid angle | Steradian | sr |
| Prefix | Symbol | meaning | Scientific Notation |
|---|---|---|---|
| giga | G | 1,000,000,000 | 10^9 |
| mega | M | 1,000,000 | 10^6 |
| kilo | k | 1,000 | 10^3 |
| hecto | h | 100 | 10^2 |
| deka | da | 10 | 10 |
| deci | d | 0.1 | 10^(-1) |
| centi | c | 0.01 | 10^(-2) |
| milli | m | 0.001 | 10^(-3) |
| micro | µ | 0.000,001 | 10^(-6) |
| nano | n | 0.000,000,001 | 10^(-9) |