Find w For AC RLC Circuit When Emf is In Phase With Current

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In summary, the conversation is discussing an AC RLC circuit with an inductor in series with a parallel capacitor and resistor. The main question is at what frequency (w) is the emf in phase with the current? The conversation also touches on the concept of reactance and how it affects the phase difference between voltage and current. The conversation ends with a question about how to calculate the impedance of a capacitor and inductor.
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scorpius1782
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Homework Statement



I have an AC RLC circuit with the inductor in series with parallel capacitor and resistor.

At what w is the emf in phase with the current?

Homework Equations





The Attempt at a Solution



I'm suppose to know this from a previous class but as a transfer student my classes never dealt with phase or RLC circuits. Any help would be phenomenal.

The question is specifically asking if ##w=\frac{1}{\sqrt{LC}}##
 
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  • #2
What exactly within an electrical system causes the phase of the current to differ from the phase of the voltage?
 
  • #3
The inductor resists changes in current so voltage changes happen more quickly and vice versa at the capacitor. (I just discovered ELI the ICE man). So, would this mean that the peak would happen every 90 degrees? How would I relate the angle to w?
 
  • #4
The phase of the current will differ from the phase of the voltage if there is reactance present within the network. If the voltage and the current are completely in phase with one another, it implies that the load is completely resistive (imaginary portion of the impedance is zero). Do you know how to calculate the impedance of a capacitor and inductor?
 
  • #5
I see you found my other post! I'll discuss this there.
 

1. What is the formula for finding w in an AC RLC circuit when the EMF is in phase with the current?

The formula for finding w in this scenario is w = 1/√(LC), where L is the inductance of the circuit and C is the capacitance.

2. How do you determine the inductance and capacitance values in an AC RLC circuit?

The inductance and capacitance values can be determined by measuring the physical properties of the circuit components, such as the number of turns in the inductor or the size of the capacitor. They can also be calculated using equations based on the circuit's geometry and materials.

3. What does it mean when the EMF is in phase with the current in an AC RLC circuit?

When the EMF (electromotive force) is in phase with the current, it means that the voltage and current are reaching their maximum and minimum values at the same time. This indicates that the circuit is in resonance, with the energy being transferred back and forth between the inductor and capacitor without any energy loss.

4. How does changing the inductance or capacitance affect w in an AC RLC circuit?

Changing the inductance or capacitance in an AC RLC circuit will affect the value of w, as it is directly proportional to the square root of the product of these two values. Increasing the inductance or capacitance will result in a decrease in w, while decreasing either value will result in an increase in w.

5. What is the significance of finding w in an AC RLC circuit when the EMF is in phase with the current?

Finding w in this scenario allows us to determine the resonant frequency of the circuit, which is the frequency at which the circuit is most efficient and has the highest amplitude of current. This can be useful in designing and optimizing electronic circuits for specific purposes.

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