AMT Prep – Airframe: Aircraft
Electrical Systems Exam 2025
Questions and Answers 100% Pass
Aircraft electrical junction boxes located in a fire zone are usually constructed of
a. aluminum sheets
b. carbon steel
c. stainless steel - ✔✔c. stainless steel
To test generator or motor armature windings for opens,
a. place armature in a growler and connect a 110V test light on adjacent segments; light
should light
b. check adjacent segments on commutator with an ohmmeter on the high resistance
scale
c. use a 12/24V test light between the armature core segments and the shaft - ✔✔a.
place armature in a growler and connect a 110V test light on adjacent segments; light
should light
If the reverse current cutout relay contact points fail to open after the generator output
has dropped below battery potential, current will flow through the generator armature
COPYRIGHT © 2025 BY OLIVIA WEST, ALL RIGHTS RESERVED 1
,a. in the normal direction and through the shunt field opposite the normal direction
b. and the shunt field opposite the normal direction
c. opposite the normal direction and through the shunt field in the normal direction -
✔✔c. opposite the normal direction and through the shunt field in the normal direction
What is the advantage of a circuit breaker when compared to a fuse?
a. It is easily replaced
b. It controls current flow
c. It is resettable and reusable - ✔✔c. It is resettable and reusable
A certain switch is described as a single-pole, double-throw (SPDT) switch. The throw
of a switch indicates the number of
a. circuits each pole can complete through the switch
b. terminals at which current can enter or leave the switch
c. places at which the operating device (toggle, plunger, etc.) will come to rest and at the
same time open or close a circuit - ✔✔a. circuits each pole can complete through the
switch
The circuit breaker in the instrument lighting system protects the
a. lights from too much current
b. wiring from too much current
c. wiring from too much voltage - ✔✔b. wiring from too much current
Circuits that must be operated only in an emergency or whose inadvertent activation
could endanger a system frequently employ
a. guarded switches
COPYRIGHT © 2025 BY OLIVIA WEST, ALL RIGHTS RESERVED 2
,b. push-pull-type circuit breakers only (no switches)
c. spring-loaded to off toggle or rocker switches - ✔✔a. guarded switches
What is the voltage drop for a No. 18 copper wire 50 feet long to carry 12.5 amperes,
continuous operation?
Use the formula VD = RLA
VD = Voltage drop
R = Resistance per ft = .00644
L = Length of wire
A = Amperes
a. 1/2V
b. 1V
c. 4V - ✔✔c. 4V
The pin section of an AN/MS connector is normally installed on
a. the power supply side of a circuit
b. the ground side of a circuit
c. either side of a circuit (makes no difference) - ✔✔b. the ground side of a circuit
Which of the following are considered circuit-protective devices that are used in aircraft
electrical systems?
a. Circuit breakers, relays, and current limiters
b. Circuit breakers, fuses, and current limiters
COPYRIGHT © 2025 BY OLIVIA WEST, ALL RIGHTS RESERVED 3
, c. Circuit breakers, capacitors, and current limiters - ✔✔b. Circuit breakers, fuses, and
current limiters
The type of electric wire terminals used for most aircraft applications, in addition to
providing good current carrying capabilities, are designed primarily
a. to prevent circuit failure due to terminal disconnection
b. for uncomplicated and rapid circuit connection and disconnection
c. for permanent connection to the circuit - ✔✔a. to prevent circuit failure due to
terminal disconnection
To help minimize radio interference a capacitor will largely eliminate and provide a
steady direct current if the capacitor is connected to the generator in
a. parallel
b. series
c. series/parallel - ✔✔a. parallel
Oil canning of the sides of aluminum or steel electrical junction boxes is considered to
be
a. normal operation in vibration prone areas
b. a shorting hazard
c. acceptable operation - ✔✔b. a shorting hazard
When adding a rheostat to a light circuit to control the light intensity, it should be
connected in
a. parallel with the light
b. series with the light
COPYRIGHT © 2025 BY OLIVIA WEST, ALL RIGHTS RESERVED 4
Electrical Systems Exam 2025
Questions and Answers 100% Pass
Aircraft electrical junction boxes located in a fire zone are usually constructed of
a. aluminum sheets
b. carbon steel
c. stainless steel - ✔✔c. stainless steel
To test generator or motor armature windings for opens,
a. place armature in a growler and connect a 110V test light on adjacent segments; light
should light
b. check adjacent segments on commutator with an ohmmeter on the high resistance
scale
c. use a 12/24V test light between the armature core segments and the shaft - ✔✔a.
place armature in a growler and connect a 110V test light on adjacent segments; light
should light
If the reverse current cutout relay contact points fail to open after the generator output
has dropped below battery potential, current will flow through the generator armature
COPYRIGHT © 2025 BY OLIVIA WEST, ALL RIGHTS RESERVED 1
,a. in the normal direction and through the shunt field opposite the normal direction
b. and the shunt field opposite the normal direction
c. opposite the normal direction and through the shunt field in the normal direction -
✔✔c. opposite the normal direction and through the shunt field in the normal direction
What is the advantage of a circuit breaker when compared to a fuse?
a. It is easily replaced
b. It controls current flow
c. It is resettable and reusable - ✔✔c. It is resettable and reusable
A certain switch is described as a single-pole, double-throw (SPDT) switch. The throw
of a switch indicates the number of
a. circuits each pole can complete through the switch
b. terminals at which current can enter or leave the switch
c. places at which the operating device (toggle, plunger, etc.) will come to rest and at the
same time open or close a circuit - ✔✔a. circuits each pole can complete through the
switch
The circuit breaker in the instrument lighting system protects the
a. lights from too much current
b. wiring from too much current
c. wiring from too much voltage - ✔✔b. wiring from too much current
Circuits that must be operated only in an emergency or whose inadvertent activation
could endanger a system frequently employ
a. guarded switches
COPYRIGHT © 2025 BY OLIVIA WEST, ALL RIGHTS RESERVED 2
,b. push-pull-type circuit breakers only (no switches)
c. spring-loaded to off toggle or rocker switches - ✔✔a. guarded switches
What is the voltage drop for a No. 18 copper wire 50 feet long to carry 12.5 amperes,
continuous operation?
Use the formula VD = RLA
VD = Voltage drop
R = Resistance per ft = .00644
L = Length of wire
A = Amperes
a. 1/2V
b. 1V
c. 4V - ✔✔c. 4V
The pin section of an AN/MS connector is normally installed on
a. the power supply side of a circuit
b. the ground side of a circuit
c. either side of a circuit (makes no difference) - ✔✔b. the ground side of a circuit
Which of the following are considered circuit-protective devices that are used in aircraft
electrical systems?
a. Circuit breakers, relays, and current limiters
b. Circuit breakers, fuses, and current limiters
COPYRIGHT © 2025 BY OLIVIA WEST, ALL RIGHTS RESERVED 3
, c. Circuit breakers, capacitors, and current limiters - ✔✔b. Circuit breakers, fuses, and
current limiters
The type of electric wire terminals used for most aircraft applications, in addition to
providing good current carrying capabilities, are designed primarily
a. to prevent circuit failure due to terminal disconnection
b. for uncomplicated and rapid circuit connection and disconnection
c. for permanent connection to the circuit - ✔✔a. to prevent circuit failure due to
terminal disconnection
To help minimize radio interference a capacitor will largely eliminate and provide a
steady direct current if the capacitor is connected to the generator in
a. parallel
b. series
c. series/parallel - ✔✔a. parallel
Oil canning of the sides of aluminum or steel electrical junction boxes is considered to
be
a. normal operation in vibration prone areas
b. a shorting hazard
c. acceptable operation - ✔✔b. a shorting hazard
When adding a rheostat to a light circuit to control the light intensity, it should be
connected in
a. parallel with the light
b. series with the light
COPYRIGHT © 2025 BY OLIVIA WEST, ALL RIGHTS RESERVED 4
