What is the value of ω for a RLC AC circuit with given parameters?

In summary, in order to find the reactance of a capacitor in a RLC circuit with an AC power source, you can use the formula Xc = 1 / (2πfC), where ω = 2πf and f is the frequency in Hz. Your given values for R, L, C, and f can be used to solve for the reactance of the capacitor. Just be aware that your teacher may refer to ω as simply the frequency, but it actually represents the angular frequency in the formula.
  • #1
musiliu
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0

Homework Statement



I am given a RLC circuit with a AC power source (e.g. signal generator), and i want to find the reactance of the capacitor.

Given: R = 2200 Ohms, L = .025 H, C = (1 x 10-9) F, V0 = 5 V
f = 3000 Hz

Homework Equations



edit: Sorry i wrote wrong formula.. here is the correct one:

Reactance of Capacitor = 1 / ω C

The Attempt at a Solution



I know how to solve this problem, but i am not sure what value to use for ω.

My teacher refers to ω as the "frequency", but isn't it supposed to be ω = 2 pi f ?

So, simply put, am i supposed to use the 3000 Hz as my ω, or do i use 2 pi f as my ω?
 
Last edited:
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  • #2
Use ω = 2 π f. Also there is no V0 in the reactance.
 
  • #3
i learned that ω is the angular frequency.. so am i supposed to use ω = 2 pi f for this problem? i am confused since my teacher keeps calling ω the frequency and not the angular frequency...
 
  • #4
musiliu said:
i learned that ω is the angular frequency.. so am i supposed to use ω = 2 pi f for this problem? i am confused since my teacher keeps calling ω the frequency and not the angular frequency...
It is a bit confusing at first because your teacher is cutting corners. You can tell whether one is talking about ω or about f by looking at the units. When you see rad/s (or s-1), it is ω. When you see Hz (or cycles per second), it is f.
 
  • #5


As a scientist, it is important to use the correct values and equations in your calculations. In this case, you are correct that ω is typically defined as 2πf, where f is the frequency in Hz. So, in this problem, you would use ω = 2π(3000 Hz) = 18849.56 radians/second.

It is also important to note that the reactance of a capacitor is frequency-dependent, so it is important to use the correct value for ω in your calculations to get an accurate result. Using the wrong value for ω could lead to incorrect conclusions about the behavior of the RLC circuit.

In summary, always use the correct equations and values in your calculations to ensure accurate and reliable results.
 

1. What is an RLC AC circuit?

An RLC AC circuit is a type of electrical circuit that contains a resistor (R), an inductor (L), and a capacitor (C) connected in series or in parallel. It is used to study the behavior of alternating current (AC) and is commonly found in electronic devices such as radios, televisions, and computers.

2. How does an RLC AC circuit work?

An RLC AC circuit works by using the properties of its components to manipulate the flow of AC current. The resistor limits the current flow, the inductor stores energy in its magnetic field, and the capacitor stores energy in its electric field. Together, these components create a resonant circuit that can amplify or attenuate specific frequencies of AC current.

3. What is the resonant frequency of an RLC AC circuit?

The resonant frequency, denoted by f, is the frequency at which an RLC AC circuit has its maximum current or voltage amplitude. It is determined by the values of the inductor and capacitor in the circuit and can be calculated using the formula f = 1/(2π√(LC)), where L is the inductance in henries and C is the capacitance in farads.

4. What is the phase difference between current and voltage in an RLC AC circuit?

In an RLC AC circuit, the current and voltage can be in phase (0 degrees), out of phase (90 degrees), or somewhere in between. The phase difference, denoted by ω, depends on the values of the components and the frequency of the AC current. It can be calculated using the formula ω = arctan((ωL - 1/(ωC))/R), where ω is the angular frequency in radians per second, L is the inductance in henries, C is the capacitance in farads, and R is the resistance in ohms.

5. How does the frequency affect an RLC AC circuit?

The frequency of an AC current can greatly affect the behavior of an RLC AC circuit. At the resonant frequency, the circuit has its maximum current or voltage amplitude. At frequencies below or above the resonant frequency, the circuit will experience different levels of attenuation or amplification. Additionally, the phase difference between current and voltage also changes with frequency, impacting the overall behavior of the circuit.

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