RLC Circuit: Calculate Resonant Frequency, Reactance & Impedence

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SUMMARY

The resonant frequency of the RLC series circuit with R=500Ω, L=0.4mH, and C=100pF is calculated to be 795.77 kHz using the formula f = 1/2π√(LC). At resonance, the inductive reactance (XL) is 2000Ω, and the capacitive reactance (XC) is approximately 1999.9998Ω. The impedance at resonance equals the resistance, which is 500Ω. The RMS current at resonance is 0.002A, and the RMS voltage across the resistor, inductor, and capacitor are 1V, 4V, and 3.99998V respectively. A discrepancy in the inductance value (0.4mH vs. 0.4H) was noted, which could affect calculations.

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k31453
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This is my question 1.

and this is my question 2.

in a RLC series circuit show above are replaced following : R=500Ω L=0.4mH and C=100pF
the circuit is connected to the terminals of an ac source with an rms voltage of 1V, and a variable frequency calculate the following
A) resonant frequency
ans: f = 1/2*pi*sqrt(LC)
= 1/(2*pi*sqrt(0.0004 * 100 * 10^-12)
= 795.77 Khz

b) the inductive and capacitive reactance at resonance
ans: XL = 2*pi*f*L
= 2*pi* 795.775*10^3*0.0004
= 2000 ohm

Xc = 1/(2*pi*f*C)
= 1/(2*pi* 795.775*10^3 * 100 * 10^-12)
= 1999.9998 ohm

C) the impedance at resonance

ans : impedence of resonance is resistance of circuit : z = R = 500 ohm

D) the rms current at resonance
ans: I = V/R = 1/500 = 0.002A

E) the rms voltage across each element at resonance
Ans: Vr = IR
= 0.002 * 500
= 1V

VL = IXL
= 0.002 * 2000
= 4V

Vc = IXc
= 0.002 * 1999.99
= 3.99998 V

So am i doing it right?? because
i got another reply that says this :


 
Last edited by a moderator:
Physics news on Phys.org
In your calculation you have used L = 0.4mH but the printed question has L = 0.4H
 

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