A very useful tool that instantly coverts between the major temperature units Fahrenheit, Celsius, and Kelvin.
Just enter the temperature value and click the "Submit" button.
Nov 23, 2010
Nov 22, 2010
Nov 21, 2010
Conductor colour identification
| Neutral of a.c. | Phase 1 of a.c. | Phase 2 of a.c. | Phase 3 of a.c. | |
|---|---|---|---|---|
| Marking | N | L1 | L2 | L3 |
| Colour | Blue | Brown | Black | Grey |
Nov 12, 2010
SI units
In Europe and the UK, the units for measuring different properties
are known as SI units. SI stands for Système Internationale.
All units are derived from seven base units.
SI-derived units:
[Electrical Installation Calculations Basic, 8th Edition - p5,6]
are known as SI units. SI stands for Système Internationale.
All units are derived from seven base units.
| Base quantity | Base unit | Symbol |
|---|---|---|
| Time | Second | s |
| Electrical current | Ampere | A |
| Length | Metre | m |
| Mass | Kilogram | kg |
| Temperature | Kelvin | K |
| Luminous intensity | Candela | cd |
| Amount of substance | Mole | mol |
SI-derived units:
| Derived quantity | Name | Symbol |
|---|---|---|
| Frequency | Hertz | Hz |
| Force | Newton | N |
| Energy, work, quantity of heat | Joule | J |
| Electric charge, quantity of electricity | Coulomb | C |
| Power | Watt | W |
| Potential difference, electromotive force | Volt | V or U |
| Capacitance | Farad | F |
| Electrical resistance | Ohm | Ω |
| Magnetic flux | Weber | Wb |
| Magnetic flux density | Tesla | T |
| Inductance | Henry | H |
| Luminous flux | Lumen | lm |
| Area | Square metre | m² |
| Volume | Cubic metre | m³ |
| Velocity, speed | Metre per second | m/s |
| Mass density | Kilogram per cubic metre | kg/m³ |
| Luminance | Candela per square metre | cd/m² |
SI unit prefixes:
| Name | Multiplier | Prefix | Power of 10 |
|---|---|---|---|
| Tera | 1000 000 000 000 | T | 1×1012 |
| Giga | 1000 000 000 | G | 1×109 |
| Mega | 1000 000 | M | 1×106 |
| Kilo | 1000 | k | 1×103 |
| Milli | 0.001 | m | 1×10-3 |
| Micro | 0.000 001 | µ | 1×10-6 |
| Nano | 0.000 000 001 | η | 1×10-9 |
| Pico | 0.000 000 000 001 | ρ | 1×10-12 |
[Electrical Installation Calculations Basic, 8th Edition - p5,6]
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