AMT AMT Avionics & Electrical Systems 1 — Questions and Answers
Question 1: What is the standard voltage for most general aviation aircraft electrical systems?
- 12 volts DC
- 24 volts DC
- 28 volts DC (Correct answer)
- 115 volts AC
Correct answer: 28 volts DC
Most general aviation and military aircraft use a 28-volt DC electrical system as the standard operating voltage.
Question 2: Which federal regulation governs the installation of avionics and electrical equipment in US-certificated aircraft?
- 14 CFR Part 23
- 14 CFR Part 43 (Correct answer)
- 14 CFR Part 91
- 14 CFR Part 121
Correct answer: 14 CFR Part 43
14 CFR Part 43 governs maintenance, preventive maintenance, rebuilding, and alteration of aircraft, including avionics and electrical system work.
Question 3: What device protects an aircraft electrical circuit from overcurrent conditions?
- Voltage regulator
- Circuit breaker or fuse (Correct answer)
- Diode
- Capacitor
Correct answer: Circuit breaker or fuse
Circuit breakers and fuses protect electrical circuits by interrupting current flow when it exceeds a safe level.
Question 4: When troubleshooting an aircraft avionics system, what instrument is most commonly used to measure resistance?
- Oscilloscope
- Multimeter (ohmmeter function) (Correct answer)
- Ammeter
- Voltmeter
Correct answer: Multimeter (ohmmeter function)
A multimeter set to the ohmmeter function measures resistance in wiring and components during avionics troubleshooting.
Question 5: What type of wire insulation is required for aircraft electrical wiring exposed to high-temperature engine compartment areas?
- PVC insulation
- Rubber insulation
- MIL-SPEC high-temperature insulation (e.g., PTFE) (Correct answer)
- Standard household wiring insulation
Correct answer: MIL-SPEC high-temperature insulation (e.g., PTFE)
MIL-SPEC high-temperature wiring such as PTFE (Teflon) insulated wire is required in engine compartments to withstand extreme heat.
Question 6: What is the purpose of a bus bar in an aircraft electrical system?
- To convert AC power to DC power
- To distribute electrical power to multiple circuits from a common point (Correct answer)
- To store electrical energy
- To regulate generator output voltage
Correct answer: To distribute electrical power to multiple circuits from a common point
A bus bar serves as a common distribution point that routes electrical power from the source to multiple individual circuits.
AMT AMT Avionics & Electrical Systems 1
What is the standard voltage for most general aviation aircraft electrical systems?