AC Circuit Analysis & Power Flashcards
7 cards from real CET practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 AC Circuit Analysis & Power flashcards as text
The skin effect in AC conductors causes current to concentrate at the:
Answer: Outer surface of the conductor
The skin effect forces AC current toward the outer surface of a conductor, increasing effective resistance at higher frequencies.
In a parallel RLC circuit, what condition defines resonance?
Answer: Susceptances cancel and total current is minimum
At parallel resonance, inductive and capacitive susceptances cancel, minimizing total current and maximizing impedance.
What is the RMS value of a sine wave with a peak voltage of 170 V?
Answer: 120.2 V
VRMS = Vpeak / √2 = 170 / 1.414 ≈ 120.2 V.
Power factor correction in industrial facilities is most commonly achieved by adding:
Answer: Capacitor banks in parallel with inductive loads
Capacitor banks supply leading reactive power that cancels the lagging reactive power of inductive loads, improving power factor.
In an AC circuit, complex power S is expressed as:
Answer: S = P + jQ
Complex power S = P + jQ, where P is real (true) power in watts and Q is reactive power in VAR.
What is the bandwidth of a series resonant circuit with f0 = 10 kHz and Q = 50?
Answer: 200 Hz
BW = f0 / Q = 10,000 / 50 = 200 Hz.
Which waveform has an RMS value equal to its average value?
Answer: Square wave
A perfect square wave alternates between two equal and opposite values, so its RMS and average (of the absolute value) are both equal to the peak value.