ETC Electrical & Electronic Systems Flashcards
6 cards from real ETC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 ETC Electrical & Electronic Systems flashcards as text
What instrument is used to measure electrical resistance in a circuit?
Answer: Ohmmeter
An ohmmeter measures electrical resistance in ohms and must be used on a de-energized circuit.
In a three-phase power system, what is the phase angle between each phase?
Answer: 120 degrees
In a balanced three-phase system, each of the three phases is separated by 120 electrical degrees.
What does a power factor of 1.0 indicate about a circuit?
Answer: Current and voltage are perfectly in phase
A power factor of 1.0 means current and voltage are in phase, indicating a purely resistive load with no reactive power.
Which type of circuit protection device automatically resets after a fault is cleared?
Answer: Circuit breaker
A circuit breaker can be reset after tripping, while a fuse must be replaced because its element melts during a fault.
What is the function of a transformer in an electrical distribution system?
Answer: To change voltage levels between circuits
A transformer uses electromagnetic induction to step voltage up or down between two circuits without direct electrical connection.
When working on energized electrical equipment, what NFPA 70E boundary requires rubber insulating gloves?
Answer: Restricted Approach Boundary
NFPA 70E defines the Restricted Approach Boundary where rubber insulating gloves and arc-rated PPE are mandatory.