| English | Prefix |
|---|---|
| Bahasa Melayu | Imbuhan |
| 中文 | 词头 |
Definition
A word or symbol placed before a unit to indicate a multiple or fraction of it, such as kilo- (10³) or milli- (10⁻³).
In exam terms
A prefix is a word or symbol placed before a unit to show a multiple or fraction of that unit as a power of ten. It saves writing very large or very small numbers in full.
Common prefixes in SPM include kilo- (k, 10³), centi- (c, 10⁻²), milli- (m, 10⁻³), micro- (μ, 10⁻⁶), nano- (n, 10⁻⁹), mega- (M, 10⁶) and giga- (G, 10⁹). For example, 1 km = 1000 m = 1 × 10³ m, and 5 mA = 5 × 10⁻³ A. A correct sentence: The prefix kilo- means one thousand, so 3 kW = 3000 W.
Do not confuse prefix with unit
Do not confuse a prefix with the unit itself. In km, k is the prefix (10³) and m is the unit (metre).
Also watch the symbol m: capital M means mega- (10⁶) but lowercase m means milli- (10⁻³) or the metre, so read carefully.
In Paper 2 you often must remove prefixes before substituting into a formula, for example change 20 cm to 0.20 m or 2 kV to 2000 V. Converting prefixes wrongly is a common cause of lost marks.
Source: DSKP KSSM Physics Form 4 and 5 (Versi English) (Bahagian Pembangunan Kurikulum (BPK), KPM)