# frequency units

#### samjesse

Joined Sep 14, 2008
212
Hi

I ofter come across what seams to be a confusing issue.

f = 1/2pi root(LC)
vs.
f = 1/root(LC)

the 2 pi is missing in the second equation.

does this mean the first is in Hz and the second is number of cycles per 360° rotation?

thx

#### KL7AJ

Joined Nov 4, 2008
2,208
Hi

I ofter come across what seams to be a confusing issue.

f = 1/2pi root(LC)
vs.
f = 1/root(LC)

the 2 pi is missing in the second equation.

does this mean the first is in Hz and the second is number of cycles per 360° rotation?

thx
The second version is in "angular frequency" which is a bit more elegant for some analytical work.

eric

#### steveb

Joined Jul 3, 2008
2,431
The second version is in "angular frequency" which is a bit more elegant for some analytical work.

eric
Yes, and traditionally the greek letter omega ($\omega$ ) is used for angular frequency with units of radians/second, while $f$ is typically used for cyclic frequency measured in units of Hz=cycles/second.

However, this is just tradition in physics/engineering, and it is best to clearly define it whenever frequency is discussed.

I like to use the word "cyclic" to qualify frequency $f={{1}\over{T}}$, where $T$ is the period. For many years I called $f$ frequency and $\omega$ angular frequency. However, if you just say frequency, it's ambiguous. However, the term cyclic-frequency makes it more clear.

By the way, does anyone know of another term for cyclic-frequency. Since the day I decided to use this terminology, I tried to think of another word for it, but never found a better one. I often wonder if I'm missing another obvious choice.