AC Theory, Level II - Lesson 5: Understanding and Working with Parallel RC Circuits
Considering the parallel RC circuit shown, decide true or false for each of the following statements. 1. Current in the capacitive branch is in-phase with the voltage. 2. The current in the resistive branch is in-phase with the voltage. 3. Current in the capacitive branch leads the current in the resistive branch by 90°.Answer 3 4. Voltages across the resistive and capacitive branches are 90° out-of-phase.
1. False 2. True 3. True 4. False
Solve for the total capacitance in the circuit shown.
10 µF
A parallel RC circuit has a resistance of 470 ohms, a reactance of 330 ohms, and an applied voltage of 470 volts. Solve for the impedance of the circuit by determining the branch currents and the total current. (Round the FINAL answer to one decimal place.) The values calculated for this question will be used for additional questions.
270.1Ω
A parallel RC circuit has a resistance of 470 ohms and a reactance of 330 ohms. Determine the impedance of the circuit using the formula: Z = (R x Xc)/ √(R^2+Xc^2)
270Ω
What is the value of C in a parallel RC circuit that has a resistance of 470 ohms, a reactance of 330 ohms, and an applied voltage of 470 volts, if the frequency is 1,025 hertz? Calculate to the nearest whole number of the unit specified.
471nF
What is the phase angle of a parallel RC circuit that has a resistance of 470 ohms, a reactance of 330 ohms, and an applied voltage of 470 volts, if the frequency is 1,025 hertz? (Round the FINAL answer to one decimal place.)
54.9°
A parallel RC circuit has a resistance of 470 ohms, a reactance of 330 ohms, and an applied voltage of 470 volts at 1,025 hertz. If the frequency is doubled to 2,050 hertz, what is the phase angle? Calculate your answer to the nearest whole number angle value.
71°
Solve for the total resistance in the circuit shown.
8 Ω
Given the circuit and parameters shown, solve for the following: (Round the FINAL answers to at least three decimal places in the specified unit.)
IR = 1.2A IC= 2.4A IT= 2.683A Z= 89.452Ω Power Factor = 44.721% Angle θ= 63.435° P true= 288W
Complete the following statements regarding a parallel RC circuit where the frequency is increased.
The impedance would decrease The total current would increase The capacitive reactance would decrease The phase angle would increase The power factor would decrease
Place the labels and values in the appropriate locations so that the vector diagram properly indicates the values for IR, IT, IC, the location, and value of the phase angle for the parallel RC circuit shown. (Be sure to place variables to the left and values to the right of the equals sign.)
Top Left = Ic = 2.4 Top Right = IT = 2.68 Bottom Left = Angle θ = 63.4° Bottom Right = IR = 1.2A
If a parallel RC circuit has a large IC and a small IR, the phase angle is closer to 90°.
True
In any reactive circuit, apparent power is larger than true power.
True
When more parallel paths are added to a parallel circuit, the number of current paths is increased and the total opposition of the circuit is reduced.
True
When the resistance is equal to the impedance, true power will be equal to apparent power.
True
Total current times applied voltage equals the ? .
a. Apparent power
A 120-volt AC circuit supplies a 3-ohm resistor in parallel with a 6-microfarad capacitor. What is the voltage across the capacitor?
d. 120
A 120-volt AC circuit supplies a 3-ohm resistor in parallel with a 6-microfarad capacitor. What is the voltage across the resistor?
d. 120v
Which of the vector diagrams and/or triangles shown below properly represents the resistor current, capacitor current, total current, and the location of angle theta for a parallel RC circuit that has a resistance of 470 ohms, a reactance of 330 ohms, and an applied voltage of 470 volts.
e. I. and IV.
