PHYSICAL QUANTYTI - Measurable
SCALAR QUANTYTI - don't Measurable
unit - for measurment any substence
1. funda mental 2. derived unit {make with funda unit helps}
UNIT SYSTEM -1 CGS(french/mitrik) , 2.MKS ,3. FPS (british)
- si unit use in india Applied 1april 1957 = 7funda.+ 2suplementry
| PHYSICSL QUANTITY | NAME | SYMBOLS | |
| BASE UNIT | 1. leanth 📏 | metre | m |
| 2. Mass⚖ | kilogram | kg | |
| 3. Time ⌚ | second | s | |
| 4. Electric current🔌💡 | Ampere | A | |
| 5. Thermodynamics temp. 🔥 | Kelvin | K | |
| 6. Luminous intensity 🕯️ | candela | cd | |
| 7. Amount of substence🥂🍷 | mole | mol | |
| SUPPLEMENTARY UNIT | 1. plane angle 📐 | rad | |
| 2. Solid angle 💎 | sr | ||
LENGTH -
1 meter - sevre (perish, france) of IBWM (International Bureau of Weights and Measures)में Pt -Ir alloy रोड की 0⁰C पर दो बिंदु के बीच दूरी
मीटर परिभाषा in वेट्स and measures meeting
{Kr86 flow electricity in tube get orange light wave lenth 1650763.73 guna
Cd red line wave lengt 1553 ,Cd green 1966 ,
Hg green 1831
Cd Hg colour line Wavelength lenth}
MASS - IBWM Pt -Ir रोड की 0⁰C पर MASS
1POND - 0.454 KG
TIME - 1967 decided in ISC (internation sci.. confrance ) , atomic clock Cs 919263170 बार कम्पन
lightv year -mesure for longlast length Distance covered in 1 year [9.46×10¹²km]
parsec (paralactic second) =3.08×10¹⁶m
astronomical unit - Average distance between sun ⛅ or earth 🌎 = 149.60*10⁹m
15×10¹¹
solar month - 30/31 day
leap year = 366 day
hectare =,m
| power of 10 | prefix | symbol |
| 18 | exa | E |
| 15 | peta | P |
| 12 | tera | T |
| 9 | giga | G |
| 6 | mega | M |
| 3 | kilo | k |
| 2 | hecto | h |
| 1 | deca | da |
| -18 | atto | a |
| -15 | femto | f |
| -12 | picp | p |
| -9 | nano | n |
| -6 | micro | μ |
| -3 | milli | m |
| -2 | centi | c |
| -1 | deci | d |
Area -
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