# RLC Circuit Question

Discussion in 'General Electronics Discussion' started by Zeeman2000, Mar 19, 2015.

1. ### Zeeman2000

6
1
Mar 2, 2015
Hoping someone can help. I have been studying RLC series circuits. The first set of questions gave the value of resistor, inductor and capacitor, which were calculated as follows:

To calculate resonant frequency:
fr = 1 / 2π√LC
fr = 1200Hz

To calculate Q:
Q = 2πfL / R
Q = 80

To calculate Bandwidth:
BW = fr / Q
BW = 15Hz

The question set then goes on to show another series RLC. It gives the value of the resistor, the resonant frequency, and the value of Q.

I have tried re-arranging the equations but can only find the bandwidth and have no idea how to find the inductor and capacitor values.

I have searched Google for answers but not turned up any equation to find L and C values.

Any help much appreciatted.

2. ### BobK

7,682
1,688
Jan 5, 2010
You have to choose one of them, then the other is determined by the equations.

Bob

3. ### Ratch

1,094
334
Mar 10, 2013
The second equation involves Q, R, fr, and L . You know what Q, R, and fr are, so you can find L. The first equation involves fr, L, and C. You know what fr and L are, so now you can find C.

Ratch