Impedance of practical Capacitor

In summary, the conversation discusses the impedance of a practical capacitor modeled by an ideal capacitor in parallel with a resistor. The impedance is calculated by adding the impedance of the resistor and the capacitor in parallel, and the solution should be ∠-1.5443 instead of ∠-1.519 due to a calculation error in using the incorrect angle unit.
  • #1
bigu01
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A practical capacitor can be modeled by an ideal capacitor in parallel with a resistor.Find the impedance of practical capacitor at the radian frequency ω=377rad/s.Known C1=0.1 x 10^-6F R1=1 *10^6.

I am first determining the Z, by adding the impedance of resistor and the capacitor in parallel.
And I am getting Z1(377)=10^6/(1+j37.7)= 2.6516*10^4 ∠-1.519 However book solutions gives ∠-1.5443.I would like to get some help about where my mistake is,or how should I approach the question. I know that finding the angle we should do θ=arctan(y/x) where y is the imaginary part and x is the real part.Hope I was clear and did not complicate it.
 
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  • #2
I can confirm the solution of the book. How did you calculate -1.519? Maybe just a rounding error?
 
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  • #3
mfb said:
I can confirm the solution of the book. How did you calculate -1.519? Maybe just a rounding error?

I was using the degree mode, I should have used the radian angle unit one
 
  • #4
Don't post the same problem in multiple threads. I am closing this thread.
 
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  • #5


Your approach is correct, but there may be a small calculation error in your answer. The correct answer for the impedance of the practical capacitor at ω=377rad/s should be Z1(377)=2.6516*10^4 ∠-1.5443. This is because the angle should be in radians, not degrees. So, when calculating the arctan, make sure to use the radian mode on your calculator.

Additionally, make sure you are using the correct values for C1 and R1. In the problem statement, it states that C1=0.1 x 10^-6F, which means C1=0.0000001F. It also states that R1=1*10^6, which means R1=1000000Ω. Double check these values in your calculation to ensure accuracy.

Overall, your approach is correct and it seems like a small calculation error is causing the difference in the angle compared to the book solution. Keep practicing and double checking your calculations to improve your accuracy.
 

Related to Impedance of practical Capacitor

1. What is impedance?

Impedance is the measure of opposition to the flow of an alternating current (AC) in an electrical circuit. It is represented by the symbol Z and is measured in ohms.

2. How does impedance relate to capacitors?

Impedance of a capacitor is the measure of its opposition to the flow of AC. It is affected by the capacitance value, frequency of the AC, and the resistance of the circuit.

3. Why is the impedance of a capacitor important?

The impedance of a capacitor is important because it determines how the capacitor will behave in an AC circuit. It can affect the current and voltage in the circuit, and is a crucial factor in designing electronic circuits.

4. How is the impedance of a practical capacitor different from an ideal capacitor?

An ideal capacitor has no resistance and therefore, its impedance is purely reactive. However, a practical capacitor has a non-zero resistance, which means its impedance will also have a real component. This can affect the overall performance of the capacitor in an AC circuit.

5. How can the impedance of a practical capacitor be calculated?

The impedance of a practical capacitor can be calculated using the formula Z = R + 1/(jωC), where R is the resistance, ω is the angular frequency, and C is the capacitance. Alternatively, it can also be measured using an impedance meter.

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