# Help on understanding LC circuit

Discussion in 'General Electronics Chat' started by francopolli, Jul 7, 2012.

1. ### francopolli Thread Starter New Member

Jul 7, 2012
2
0
I am a beginner and trying to understand the resonant frequency formula for a tank LC circuit. f=1/2pi*sqrt(l*c).
If i know only F and C and i need to calculate L... i can't understand why the formula becomes L=1/4*pi*pi*F*F*C
I know i am missing something here but i can't figure what.

2. ### MrChips Moderator

Oct 2, 2009
12,646
3,458
What do you not understand?
Seems clear to me.

3. ### crutschow Expert

Mar 14, 2008
13,508
3,384
To extract the L from the equation you need to take the square of both sides of the equation. Then rearrange the terms to give the value of L.

francopolli likes this.
4. ### WBahn Moderator

Mar 31, 2012
18,088
4,917
How much algebra, if any, have you had so far? That will help us explain things at a level that matches your math background.

5. ### francopolli Thread Starter New Member

Jul 7, 2012
2
0
Thank you guys! My head wasn't working
Algebra knowledge is average and i was forgetting to "square" the 2... hence i was puzzled by the "4"

BTW this site is great

6. ### WBahn Moderator

Mar 31, 2012
18,088
4,917
We all suffer from that from time to time.

In the future, try to say WHY you are having a problem and, if possible, what you think the answer should be (or what your work is coming up with, even if you know it is wrong). Best is to post your work, or at least a summary of it.

Welcome aboard!