Aircraft Electrical Systems Flashcards
7 cards from real AMT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Aircraft Electrical Systems flashcards as text
What is the primary advantage of a brushless AC generator over a brush-type generator in aircraft applications?
Answer: Reduced maintenance and elimination of brush wear and arcing
Brushless generators use rotating rectifiers instead of slip rings and brushes, eliminating a major maintenance item and source of radio interference.
An aircraft static inverter is used to:
Answer: Convert DC power to AC power for AC-dependent avionics
A static inverter converts DC (typically 28V) from the battery or DC bus into AC power (usually 115V, 400Hz) needed for certain avionics and instruments.
When connecting a ground power unit (GPU) to an aircraft, which precaution is most critical?
Answer: Verify GPU output voltage and polarity match the aircraft system before connecting
Connecting a GPU with incorrect voltage or reversed polarity can instantly damage avionics, batteries, and control systems — voltage and polarity verification is mandatory.
A diode used in an aircraft rectifier circuit allows current to flow:
Answer: Only in one direction, from anode to cathode
A diode is a one-way electrical valve that permits current to pass from anode to cathode and blocks reverse flow, enabling AC-to-DC rectification.
Aluminum wiring used in aircraft requires special terminal lugs because:
Answer: Aluminum oxide forms on the surface and increases contact resistance
Aluminum rapidly forms an insulating oxide layer at connection points; special inhibitor-filled lugs are required to displace the oxide and maintain good electrical contact.
What does a low charging rate on an aircraft ammeter indicate after engine start?
Answer: The battery is fully charged and the generator is at capacity
A low or near-zero charging rate shortly after start typically means the battery has recovered to near full charge and the generator is simply maintaining it with minimal current.
The purpose of a noise filter or EMI filter on aircraft avionics power leads is to:
Answer: Prevent high-frequency electrical noise on the bus from reaching sensitive equipment
EMI filters use capacitors and inductors to block high-frequency interference conducted along power lines that could disrupt radio and navigation equipment.