| Quantity | Unit Name | Symbol | |
|---|---|---|---|
| Base Units (7) | |||
| Length | metre | m | |
| Mass | kilogram | kg | |
| Time | second | s | |
| Electric current | ampere | A | |
| Temperature | kelvin | K | |
| Amount of substance | mole | mol | |
| Luminous intensity | candela | cd | |
| Derived Units | |||
| Speed | metre per second | m/s | |
| Acceleration | metre per second squared | m/s² | |
| Force | newton | N | |
| Pressure | pascal | Pa | |
| Energy | joule | J | |
| Power | watt | W | |
| Electric charge | coulomb | C | |
| Voltage | volt | V | |
| Resistance | ohm | Ω | |
| Frequency | hertz | Hz | |
| Magnetic flux | weber | Wb | |
| Temperature difference | degree Celsius | °C | |
| Luminous flux | lumen | lm | |
| Illuminance | lux | lx | |
| Angle | radian | rad | |
SI Units
The International System of Units (SI) defines 7 base units from which all other units are derived. It is the modern form of the metric system and the world's most widely used system of measurement.
FAQ
Q: What is the SI system?
A: The International System of Units (SI) is the standard metric system used worldwide for scientific and everyday measurements. It defines 7 base units from which all other units are mathematically derived.
Q: What are the 7 SI base units?
A: Length (metre, m), Mass (kilogram, kg), Time (second, s), Electric current (ampere, A), Temperature (kelvin, K), Amount of substance (mole, mol), Luminous intensity (candela, cd).
Q: What is a derived unit?
A: Derived units are combinations of base units. For example, speed (m/s) = length/time, force (newton, N) = kg·m/s², and energy (joule, J) = kg·m²/s².