RC Series Circuits Flashcards
The total capacitance (Ct) of a series circuit is always less than ______.
The total capacitance (Ct) of a series circuit is always less than the smallest capacitor.
To find total capacitance (Ct) in a series circuit, what formula is used?
Capacitive reactance (Xc) in a series circuit is measured in _____ and expresses the amount of __________.
Capacitive reactance (Xc) in a series circuit is measured in ohms and expresses the amount of opposition to current flow in the circuit.
As capacitance increases, current _____, and capacitive reactance ______.
As capacitance increases, current increases, and capacitive reactance decreases.
Review Question:
How is frequency measured?
Frequency is measured in cycles per second. The more cycles per second, the higher the frequency.
As frequency increases, current _____, and capacitive reactance _______.
As frequency increases, current increases, and capacitive reactance decreases.
Combining the effects of capacitance and frequency produces what formula for capacitive reactance?
Xc = 1 ÷ (2)(pie)(f)(C)
As frequency increases, Xc ______.
As frequency increases, Xc decreases.
As capacitance increases, Xc ______.
As capacitance increases, Xc decreases.
What is the formula for total capacitive reactance (Xct)?
Total Xc is determined by adding each capacitor’s capacitive reactance.
Xct = Xc1 + Xc2 + Xc3…..
The combined opposition to current flow from the resistor and capacitor is called _____. The unit of measure is ______.
The combined opposition to current flow from the resistor and capacitor is called impedance (Z). The unit of measure is ohms.
What is the formula for total impedance (Zt)?
Zt = Sq Rt of R2 + Xc2
What steps is needed to solve for total current and voltage drops in an example circuit?
- Calculate capacitive reactance. Xc = 1 ÷ (2)(pie)(f)(C)
- Find total capacitive reactance. Xct = Xc1 + Xc2……
- Determine total resistance. Rt = R1 + R2…..
- Solve for total impedance. Zt = Square Root of: Rt2 + Xct2
- Solve for total current. It x ‘R’ = V
- Solve for voltage drops.
- Er = It x R
- Ec = It x Xc
- Check the results. Applied Voltage Ea = Sq Rt of: Ert2 + Ect2
In AC circuits with reactance, what are the three types of power?
Real - the power consumed by the resistor.
Reactive - the power consumed by the capacitor.
Appearent - the combination of real power and reactive power.
What is the phase relationship between current and voltage across a capacitor?
I leads E by 90 degrees.
To help remember this relationship, remember the word ICE. Current (I) in a capacitive circuit (C) is before voltage (E). Current leads voltage.
RL series circuits consist of _______ and _______ connected in series.
inductors, resistors
In RL series circuits, R and XL oppose _____at right angles
oppose current at right angles
In RL series circuits, _____ is the same at any point in the circuit
current is the same at any point in the circuit
In RL series circuits, _____ and ____ are at right angles.
In RL series circuits, ER and EL are at right angles.
In an RL series circuit, as the phase angle approaches 90 degrees, the circuit is mostly _______.
inductive
In RL series circuits _____ leads current by 90 degrees.
voltage leads current by 90 degrees
In an RL series circuit, as the phase angle approaches 0 degrees, the circuit is mostly _______.
resistive
When measuring across a resistor, _______ and _______ are always in phase.
voltage and current
As XL increases, a circuit becomes more _______.
inductive
When XL is large compared to R in an RL series circuit, the circuit is _______.
inductive
