Rules to write name and symbol for units of S.I. system Physics Notes
Rules to write name and symbol for units of S.I. system:
Following are the most important rules of the SI regarding the writing of quantities, names and symbols of the units; they are valid in general, i. e., also for units that do not belong to the SI.
1. Symbols and prefixes are the same in all languages.
2. Symbols are written in lower case, except when the unit is derived from a proper name.
3. Symbols are never pluralized. e.g. 65 g (not: 65 gs), 15 km (not: 15 kms)
4. An oblique stroke ( / ) is always used with symbols rather than the word, “per”. For example km/h (not: km per hour). However, kilometre per hour (not: kilometre/hour), when writing units in full.
5. The units that are named after scientists, are not written with a capital letter. For example the unit of force named after Issac Newton is written as ‘newton’.
6. The symbols that are named after scientists are written with capital initial letter. For example the unit newton has symbol N.
7. Most single units will be written in one word, e.g., centimetre, millimeter, kilogram, kilowatt (not: centi-metre, kilo-gram etc.).
8. Always place the symbol behind the numeral for example 16.8 km, 650 g, 350 mL.
9. A number and a symbol should never be separated by an adjective.
Some examples of representation of the unit of measurement:
