Electrical Theory & Fundamentals Flashcards
7 cards from real CEA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Electrical Theory & Fundamentals flashcards as text
An inductor in a DC circuit, after reaching steady state, acts as:
Answer: A short circuit (wire)
At DC steady state, an ideal inductor has zero reactance and acts as a short circuit (low-resistance wire).
What is the relationship between inductive reactance (XL) and frequency?
Answer: XL increases as frequency increases
XL = 2πfL, so inductive reactance increases proportionally with frequency.
Three 120 V light bulbs are connected in series across 360 V. What voltage appears across each bulb?
Answer: 120 V
In series, voltage divides equally among identical loads: 360/3 = 120 V per bulb.
What is the term for the ratio of true power to apparent power in an AC circuit?
Answer: Power factor
Power factor (PF) = True Power (W) / Apparent Power (VA), ranging from 0 to 1.
Electrical energy is measured in:
Answer: Kilowatt-hours
Kilowatt-hours (kWh) is the commercial unit of electrical energy; utility bills are measured in kWh.
What is the primary purpose of a transformer?
Answer: Change voltage and current levels
A transformer uses electromagnetic induction to step voltage up or down while inversely changing current.
In a series RLC circuit at resonance, what is true about the impedance?
Answer: Impedance equals only the resistance
At resonance, XL = XC and they cancel, leaving total impedance equal to resistance only.