Basic Electrical Principles Flashcards
7 cards from real EIAT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Basic Electrical Principles flashcards as text
What is the effect of increasing temperature on the resistance of most metallic conductors?
Answer: Resistance increases
In most metals, higher temperatures cause increased atomic vibration, which impedes electron flow and raises resistance.
In a parallel circuit with two branches carrying 4A and 6A respectively, what is the total current from the source?
Answer: 10 A
In a parallel circuit, total current equals the sum of branch currents: 4 + 6 = 10 A.
What is 'apparent power' in an AC circuit measured in?
Answer: Volt-amperes (VA)
Apparent power is the product of RMS voltage and RMS current in an AC circuit, expressed in volt-amperes (VA).
Which type of motor is most commonly used in elevator traction drives?
Answer: AC induction motor
AC induction motors are widely used in elevator traction drives due to their reliability, low maintenance, and efficiency with variable frequency drives.
What does a voltmeter measure and how should it be connected in a circuit?
Answer: Voltage; connected in parallel
A voltmeter measures the potential difference (voltage) between two points and must be connected in parallel across those points.
What is the purpose of a contactor in elevator electrical systems?
Answer: To switch high-current motor circuits using a low-current control signal
A contactor is an electrically operated switch that uses a small control current to open or close a high-current circuit, such as a motor power circuit.
What is the correct color code for the ground wire in US electrical installations?
Answer: Green or bare copper
In US wiring, the equipment grounding conductor is identified by green insulation, green with a yellow stripe, or bare copper.