Calculating Impedance and Voltage Drop in an RLC Circuit

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SUMMARY

The discussion focuses on calculating the impedance and voltage drop in a series RLC circuit consisting of a resistor (R = 100 Ω), an inductor (L = 0.20 H), and a capacitor (C = 3 µF) connected to an AC source (VS = 100 V, f = 200 Hz). The total circuit impedance (Zt) is calculated to be 100.97 Ω, and the total circuit current (IS) is determined to be approximately 0.99 A. The voltage drops across the resistor (VR = 140 V), inductor (VL = 352.03 V), and capacitor (VC = 371.51 V) were derived, but the user encountered issues with the maximum voltage calculations, leading to confusion regarding Kirchhoff's law.

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  • Understanding of RLC circuit components: resistor, inductor, and capacitor
  • Familiarity with AC circuit analysis and phasor diagrams
  • Knowledge of impedance calculation in series circuits
  • Proficiency in applying Kirchhoff's voltage law
NEXT STEPS
  • Learn how to calculate total impedance in RLC circuits using complex numbers
  • Study the concept of resonant frequency in RLC circuits
  • Explore the quality factor (Q) and its significance in circuit performance
  • Investigate the use of phasor diagrams for visualizing voltage and current relationships
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Electrical engineering students, circuit designers, and anyone involved in AC circuit analysis and RLC circuit optimization.

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Homework Statement


A resistor, R = 100 Ω, an inductor, L = 0.20 H and a capacitor, C = 3 µF are connected in series across an ac source of VS = 100 V and frequency, f = 200 Hz. Calculate the following for this series circuit:
a) the total circuit impedance (Zt)
b) the total circuit current (IS)
c) the voltage drop across each component (VR, VL and VC)
d) the phase angle between VS and It.
e) Draw the phasor diagram of voltages and current for the circuit.
f) What is the frequency of the ac source for maximum current to flow?
g) What is the quality factor, Q, of the circuit at the frequency calculated in part f)?




The Attempt at a Solution



R = 100 ohms
L = 0.2 henries
C = 3*10^-6 farads
Vrms = 100V therefore Vmax = 100*sqrt2 = 141.42
freq = 200Hz therefore w = 1256.64
XL=wL=251.327
Xc=1/wc=265.26

Z = sqrt[(R^2 + (XL-Xc)^2] = 100.97
Irms = Vrms/Z = 0.99 therefore Imax = 0.99*sqrt2 = 1.4

now here is where I am stuck... the voltage drop...
Voltage drop across resistor, VR = R*Imax = 140V
Voltage drop across inductor, VL = XL*Imax = 352.03
Voltage drop across capacitor, VC = Xc*Imax = 371.51

and kirchhoff says Vmax^2 = VR^2 + (VL-VC)^2

subbing in... Vmax = 74.16 which is wrong... since Vmax = 141.42



Any ideas?
 
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I think you just plugged it into your calculator wrong. I got the right answer following what you did.
 
oh god -.- thank you.
 

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