FREE AMT Aircraft Electrical Systems Questions and Answers

Question 1

In a typical large transport aircraft AC electrical system, what is the primary purpose of a Constant Speed Drive (CSD) unit?

Accepted Answer

To convert variable engine RPM into a constant generator speed.

Answer

To rectify AC voltage to DC voltage for the battery bus.

Answer

To increase the output voltage of the generator during high-demand periods.

Answer

To act as a circuit breaker in the event of a generator fault.

Question 2

A technician is troubleshooting a circuit that repeatedly trips its protective device shortly after being reset. The aircraft is in a high-vibration environment. Which of the following is the most likely cause?

Accepted Answer

An intermittent short to ground in the wiring.

Answer

A faulty circuit breaker.

Answer

The battery is overcharged.

Answer

The load on the circuit is too low.

Question 3

When comparing a typical aircraft DC alternator to a DC generator, what is a significant advantage of the alternator?

Accepted Answer

It produces sufficient charging current at lower engine RPMs.

Answer

It can produce electrical power even with a completely dead battery.

Answer

It is less susceptible to damage from reversed polarity.

Answer

It does not require a voltage regulator for operation.

Question 4

According to 14 CFR Part 25, if the ability to replace a fuse is essential to safety in flight, what is the minimum number of spare fuses that must be available?

Accepted Answer

At least 50% of the number of fuses of each rating.

Answer

One for each essential circuit.

Answer

At least 25% of the number of fuses of each rating.

Answer

A number equal to the total number of fuses installed.

Question 5

While reviewing an aircraft wiring diagram, a technician notes a component symbol consisting of a coil and a set of contacts. When the coil is energized, it mechanically closes the contacts in a separate circuit. What does this symbol represent?

Accepted Answer

A relay.

Answer

A diode.

Answer

A resistor.

Answer

A capacitor.

Question 6

Which type of aircraft battery is known for being lightweight and having a high energy density, but is also susceptible to thermal runaway if not properly managed by a sophisticated charging and monitoring system?

Accepted Answer

Lithium-ion (Li-ion).

Answer

Vented lead-acid.

Answer

Nickel-cadmium (Ni-Cd).

Answer

Sealed lead-acid (VRLA).