Solve Impedance Problem: 50nF Capacitor & 47kΩ Resistor

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AI Thread Summary
The discussion revolves around calculating the current in a circuit with a 50nF capacitor and a 47kΩ resistor, powered by a 120Vrms AC voltage at 350Hz. The initial calculation for capacitive reactance (Xc) was incorrect, leading to a current estimate of 2.51mA, while the correct answer is 3.545sin(700π + 11°)mA. Participants emphasized the importance of using the correct formula for Xc, which is Xc = -1/(ωC), and highlighted the need for proper notation. The conversation stresses the significance of reviewing lecture materials for accurate calculations. Overall, the thread serves as a guide for solving impedance problems in AC circuits.
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Homework Statement



A circuit consists of a 50nF capacitor in series with a 47kΩ resistor. An AC voltage of 120Vrms at
350Hz is applied to the circuit.

(a) Determine the current flowing through the circuit.
(b) Sketch the impedance diagram for the circuit at this frequency.

Homework Equations



Xc , diagram , V = IZ

The Attempt at a Solution



First i found Xc = 1/2* pi* f * C

Then i did impedence diagram to find z and then use V = IZ to find Z

I got the answer: 2.51mA

But why it says answer is : 3.545sin(700π+11^0)mA ?
 
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k31453 said:

Homework Statement



A circuit consists of a 50nF capacitor in series with a 47kΩ resistor. An AC voltage of 120Vrms at
350Hz is applied to the circuit.

(a) Determine the current flowing through the circuit.
(b) Sketch the impedance diagram for the circuit at this frequency.

Homework Equations



Xc , diagram , V = IZ

The Attempt at a Solution



First i found Xc = 1/2* pi* f * C

That is wrong. Check your lecture notes or books.


ehild
 
ehild said:
That is wrong. Check your lecture notes or books.


ehild

isnt it Xc = 1/ angular freq.* C ??
 
k31453 said:
isnt it Xc = 1/ angular freq.* C ??

Xc = 1/ angular freq.* C means 1/angular frequency, multiplied by C. Use parentheses: Xc=-1/(ωC) and do not forget, that Xc is negative.

Show your work in detail.

ehild
 
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