Solve Parallel Resonance: L&C Values & Resistance of Coil

[drizzt72]

When placed in series a coil and capacitor resonate at a frequency of 2251Hz and when placed in parallel they resonate at a frequency of 2228Hz. At parallel resonance it is also found that a current of 5mA flows from the supply when the supply voltage is 25V r.m.s.
Determine the value of the capacitor and the inductance and the resistance of the coil.




fs = 1/(2Π√LC)

fp = 1/2Π √(1/LC-R^2/L^2 )



From the information given, I can work out the parallel resistance:

R = v<sub>s / I
= 25 / 0.005
= 5000 Ohms.

But from this I don't know which way to go. Any guidance would be much appreciated.</sub>

 

[berkeman]

When placed in series a coil and capacitor resonate at a frequency of 2251Hz and when placed in parallel they resonate at a frequency of 2228Hz. At parallel resonance it is also found that a current of 5mA flows from the supply when the supply voltage is 25V r.m.s.
Determine the value of the capacitor and the inductance and the resistance of the coil.




fs = 1/(2Π√LC)

fp = 1/2Π √(1/LC-R^2/L^2 )



From the information given, I can work out the parallel resistance:

R = v<sub>s / I
= 25 / 0.005
= 5000 Ohms.

But from this I don't know which way to go. Any guidance would be much appreciated.</sub>

<sub>The wikipedia.org article on RLC resonance is pretty good, and should help you out.

http://en.wikipedia.org/wiki/RLC_series_circuit

.</sub>