Important Formulas: Physics and measurement

 Page 1


UNIT AND DIMENSIONS
Unit :
Measurement of any physical quantity is expressed in terms of an
internationally accepted certain basic standard called unit.
* Fundamental Units.
S.No. Physical Quantity SI Unit Symbol 
1 Length Metre m  
2 Mass Kilogram Kg 
3 Time Second S 
4 Electric Current Ampere A 
5 Temperature Kelvin K 
6 Luminous Intensity Candela Cd 
7 Amount of Substance Mole mol 
 
* Supplementary Units :
S.No. Physical Quantity SI Unit Symbol 
1 Plane Angle radian r 
2 Solid Angle  Steradian Sr 
 
* Metric Prefixes :
 
S.No. Prefix Sym bol Value 
1 Centi c  10
–2
 
2 M ili  m  10
–3
 
3 M icro µ 10
–6
 
4 Nano n  10
–9
 
5 Pico p  10
–12
 
6 Kilo K 10
3
 
7 M ega M 10
6
 
 
Page 2


UNIT AND DIMENSIONS
Unit :
Measurement of any physical quantity is expressed in terms of an
internationally accepted certain basic standard called unit.
* Fundamental Units.
S.No. Physical Quantity SI Unit Symbol 
1 Length Metre m  
2 Mass Kilogram Kg 
3 Time Second S 
4 Electric Current Ampere A 
5 Temperature Kelvin K 
6 Luminous Intensity Candela Cd 
7 Amount of Substance Mole mol 
 
* Supplementary Units :
S.No. Physical Quantity SI Unit Symbol 
1 Plane Angle radian r 
2 Solid Angle  Steradian Sr 
 
* Metric Prefixes :
 
S.No. Prefix Sym bol Value 
1 Centi c  10
–2
 
2 M ili  m  10
–3
 
3 M icro µ 10
–6
 
4 Nano n  10
–9
 
5 Pico p  10
–12
 
6 Kilo K 10
3
 
7 M ega M 10
6