Exploring the AC Generator in an LRC Circuit

Click For Summary

Homework Help Overview

The discussion revolves around an AC generator in an LRC circuit, specifically analyzing the voltage, current, and phase difference in the circuit based on the provided voltage function. The participants are exploring the implications of the circuit parameters and their relationships.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning, Problem interpretation, Assumption checking

Approaches and Questions Raised

  • Participants discuss the calculation of rms voltage from peak voltage and the confusion surrounding the maximum current in the circuit. They explore the relationship between voltage, impedance, and current, questioning the need for frequency information to determine reactance. The phase difference is also examined, with references to resonance and the use of trigonometric relationships.

Discussion Status

Some participants have confirmed certain calculations, while others are seeking clarification on the necessity of frequency for determining impedance and phase difference. There is an ongoing exploration of assumptions regarding resonance and the implications for circuit behavior.

Contextual Notes

Participants note the absence of specific frequency values and the implications this has on their calculations. There is a mention of needing to assume resonance to simplify the analysis.

popo902
Messages
59
Reaction score
0

Homework Statement


An AC generator in an LRC circuit produces a voltage V(t) = 1.414sin(wt) = 1.414sin(1000t)
The values of inductance, capacitance, and resistance are shown in the diagram. Recall the w = 2pi*f.

i made a picture of the diagram:
http://i36.photobucket.com/albums/e47/jo860/lrc.jpga) What is the rms voltage supplied by the generator?

b) What is the maximum current in the circuit?

c)What is the phase difference between the AC generator and the current flowing in the current?

(I made w = omega)

Homework Equations



Vrms = Vpeak/ sqrt(2)

The Attempt at a Solution


im doing practice final and i don't have the answers
i just want to run them by some people just in case i got the thinking wrong
so for,

a) Since V(t) = Vpeak *sin(wt), Vpeak = 1.414, so then Vrms = 1.414/sqrt(2) =~ 1V, right?

b) This is one I'm mostly confused on. I'm not sure how to go about this, but I'm leaning toward the power equation except there is no power value here. This is assuming ipeak is what it's asking for...so...:(c) I remember that RLC circuits are usually conductive, so the phase would be around 90, with the current leading, right?

and that's what i have so far
 
Last edited:
Physics news on Phys.org
for (a) your answer is right.
for (b) you need to find Ipeak which can be found from voltage divided by total impedance of the circuit.
for (c) you know Z(=R+j(Xl-Xc) ) from this you find the phase difference.
 
ok
for part

b) Ipeak = Vpeak/ Z
but don't i need the value of frequency to calculate this?
because since the reactance of L anc C need the value, i need it here...
or can i assume that it's at resonance? Then Z= R :S

C) I read some more and i remembered that i could find the angle using tan = Xl - Xc/ R
but again, I need the frequency

is there something I'm missing here?
 
b) Yes you need frequency information. The supply frequency can be known from V(t)=1.414sin(1000t). Find frequency and then Z.
c) You are right.
 
oh i see now,
i solve for omega using that given equation
thank you so much!
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 21 ·
Replies
21
Views
2K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 25 ·
Replies
25
Views
3K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
4
Views
3K