# resonance frequency of L C

#### VALKETEER

Joined Mar 14, 2006
2
I have an electronics math problem that is driving me nutz.

10vAC in series with a 10k resistor, a .5mH coil, and a 560pF capacitor. Question is what is the resonance frequency?

Problem:
1
---------------------------------
Fr = 2Pi * square root(.5 mH * 560 pF)

I get (9.5 kH) do you have an idea what step Im missing?

#### Papabravo

Joined Feb 24, 2006
16,775
Originally posted by VALKETEER@Mar 14 2006, 12:24 PM
I have an electronics math problem that is driving me nutz.

10vAC in series with a 10k resistor, a .5mH coil, and a 560pF capacitor. Question is what is the resonance frequency?

Problem:
1
---------------------------------
Fr = 2Pi * square root(.5 mH * 560 pF)
I get (9.5 kH) do you have an idea what step Im missing?
[post=14976]Quoted post[/post]​
I don't know where you went wrong, but here is my solution
0.5 mH = 0.5e-3 Henry, and 560 pF = 560e-12 Farad
Rich (BB code):
Compute the denominator
2 * pi * √ (0.5e-3 * 560e-12) =
6.28 * √ (280e-15) =
6.28 * 529e-9 =
3.324e-6 and
Take the reciprocal
1 / 3.324e-6 = 300.77e3 =
301 kHz

#### VALKETEER

Joined Mar 14, 2006
2
Thanks, I see where I went wrong now.

#### hgmjr

Joined Jan 28, 2005
9,029
Originally posted by VALKETEER@Mar 14 2006, 11:24 AM
I have an electronics math problem that is driving me nutz.

10vAC in series with a 10k resistor, a .5mH coil, and a 560pF capacitor. Question is what is the resonance frequency?