1.2.3 Prefixes

Prefixes
Prefixes are the preceding factor used to represent very small and very large physical quantities in SI units.


Conversion of prefixes
Prefixes to Normal Number
Example 1
The frequency of the radio wave is 350M Hz. What is the frequency of the radio wave in Hz?
Answer
Mega (M) = 1,000,000 or 10⁶
Therefore,
350MHz = 350 x 10⁶Hz
Example 2
The thickness of a film is 25nm. What is the thickness in unit meter?
Answer
nano (n) = 0.000000001 or 10^-9
Therefore
25nm = 25 x 10^-9m
Normal number to Prefixes
Example 3
0.255 s is equal to how many ms.Answer
mili (m) = 0.001 or 10^-3
To write a normal number with prefixes, we divide the number with the value of the prefixes
0.0255 s = 0.0255 ÷ 10^-3 = 25.5 ms
Example 4
Convert 265,500,000 W into GW.Answer
Gega (G) = 1,000,000,000 or 10⁹
Therefore
265,500,000 W = 265,500,000 ÷ 10⁹ = 0.2655GW

External Link
The NIST Reference on Prefixes

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