NCATT AET UPDATED 2026 EXAMS SCRIPT QUESTIONS
AND ANSWERS SCORED A+
✔✔Proton - ✔✔• Positively charged subatomic particles that exist within the nucleus of
all atoms
• Protons are not involved in the conduction of electricity
✔✔Resistance (R) - ✔✔• Electrical characteristic of a conductor
• Opposition that a circuit, component, or substance presents to flow of electricity
• Resistance is the force that opposes or slows down another force, drops voltage, and
consumes power
• Resistance is measured in ohms
• In mathematical problems ohms of resistance is expressed by symbol "R"
✔✔Scientific Notation - ✔✔• Short way of expressing a given number between 1 and 10
multiplied by 10 to the appropriate power
✔✔Static Electricity - ✔✔• Electrical charge that may be built up on a non-conductive
surface by friction
• Static electricity serves no useful purpose
✔✔Volt (V) - ✔✔• Basic unit of electrical pressure
• A volt is the amount of force required to cause one amp of current to flow through one
ohm or resistance
• Volt is often expressed by such terms as voltage, voltage drop, potential difference,
EMF, or IR drop
✔✔Watts (W) - ✔✔• Basic unit of power that is the product of voltage multiplied by
current
• One watt is power po
produced in a circuit that has one amp of current flowing under a pressure of one volt
✔✔Working Voltage - ✔✔• Maximum amount of DC voltage that can be safely applied
across a capacitor
✔✔Alternating Current (AC) - ✔✔• Flow of electrons that continuously changes it value
in magnitude and periodically reverses direction (sine-wave)
• Alternating current is much easier to produce in large quantities as compared to DC.
The time required for one cycle of AC to occur is called the period
✔✔Apparently Power - ✔✔• Product of effective voltage and effective current which is
expressed in Volt Amps (VA) rather than Watts (W) without reference to phase shift, if
any, between voltage and current
✔✔Capacitive Reactance (XC) - ✔✔• Opposition to current flow in a circuit
,• The affect that capacitance has on an AC circuit to lead voltage in phase (ICE)
• Values are given in ohms
✔✔Delta Wound - ✔✔• Windings arranged in the shape of a triangle
• For example, on a three-phase generator, motor, or transformer, two of the phase
windings are in series, across the third (phase) winding
✔✔Effective Voltage - ✔✔• Amount of AC that produces the same amount of heat as a
corresponding value of DC
• The effective voltage of AC is referred to as the RMS valve of AC
• Unless otherwise specified, all values of AC are considered effective values
✔✔Frequency - ✔✔• Number if cycles of AC completed in one second
• Frequecy is expressed in Hertz (Hz), 1 Hz = 1 cycle of AC/Sound
• The frequency of most AC used in aircraft applications is 400 Hz
✔✔Impedanc (Z) - ✔✔• Electrical characteristic of a conductor. Impedance is the total
opposition to the flow of AC in an electrical circuit ( resistance, capacitance, and
inductance)
• Values are given in ohms
✔✔Inductive Reactance (XL) - ✔✔• Opposition to current flow in a circuit
• The affect that inductance has on an AC circuit is termed inductive reactance
• Inductance causes current to lag voltage in phase (ELI). Values are given in ohms
✔✔Phase Angle - ✔✔• Angle between two similarly varying quantities (sine-waves)
• A phase angle is the difference in angle between two sinusoidally varying quantities
that have the same frequency
✔✔Polyphase - ✔✔• Production of two or more phases of AC, or of two or more
alternating voltages of the same frequency
• The most common type of polyphase uses three phases
✔✔Power Factor - ✔✔• Ratio of actual power dissipated in an electrical system to the
input power of volts multiplied by amps
• The power factor is the ratio of power dissipated over input
✔✔Rectifier - ✔✔• Electronic device that converts AC to DC
• For example, a set of semiconductor diodes connected
✔✔Root Mean Square (RMS) - ✔✔• Effective value of sine-wave alternating current
• The RMS value is .707 of the peak value
✔✔Sine-Wave - ✔✔• Alternating current wave form produced by a rotary generator
,• Sine-waves are values of voltage and current that start at zero and smoothly rise to a
peak value; the waves smoothly fall from a peak back to zero
• The waves then rise to a peak value in a negative direction and smoothly return to
zero
• One AC cycle is produced by 360 degrees of rotation
✔✔True Power - ✔✔• Power actually available in an AC circuit
• True power is the product of the circuit voltage and the current in phase with this
voltage
•Values are given in watts
✔✔Wye Wound - ✔✔• Windings arranged in the shape of a Y
• For example, on a three-phase generator or transformer, one end of each of the three
windings is connected to form a common point
✔✔Bridge Circuits - ✔✔• Contains four impedances that form a square
• Two diagonally opposite corners are connected to an input device
• The other two diagonally opposite corners are connected to an output device
✔✔Complex Circuit - ✔✔• Contains a combination of series and parallel circuits
✔✔Joules - ✔✔• International measure of energy expended in the kilogram, meter, and
second system of units
• Also known as a Newton-meter, a Joules is the amount of work done when a force of
one newton moves an object one meter along the direction of the force
✔✔Kirchhoff's Current Law (KCL) - ✔✔• Kirchhoff's current law states that "the
algebraic sum of the current flowing away from any point in an electrical circuit is equal
to the sum of the current flowing to that point"
✔✔Kirchhoff's Resistance Law (KRL) - ✔✔• Kirchhoff's Resistance Law states that "the
total resistance in a series circuit is the sum of the individual resistances or loads in the
circuit"
✔✔Kirchhoff's Voltage Law (KVL) - ✔✔• Kirchhoff's Voltage Law states that "the
algebraic song of all the voltage drops in any closed circuit is equal to zero"
✔✔Parallel Circuits - ✔✔• Contains more than one path for current
• Circuit components are connected directly across each other
• Current is divided between each branch in the circuit
✔✔Power - ✔✔• Product of applied voltage and current power in a DC circuit
• Product of applied voltage and the current in phase with the voltage in an AC circuit
✔✔Resistors in Series Circuits - ✔✔• Causes a reduction of current in one circuit
, ✔✔Resistors in Parallel Circuits - ✔✔• Causes a reduction of current in multiple circuits
✔✔Series Circuits - ✔✔• Contains only one path for current, making current common
through all components
• Series circuit components are connected end-to-end
✔✔Voltage Drop - ✔✔• Reduction in voltage caused by current flowing through a
resistor
• Voltage drop is called and IR (current X resistance) drop
✔✔Basic Troubleshooting Tools - ✔✔Multimeter
• Most versatile electrical measuring instrument used by aircraft technicians
• A multimeter has voltage, current, and resistance in an electrical circuit
• Each multimeter has a voltmeter, ammeter, and ohmmeter which are used to analyze
values in electrical circuits
✔✔Voltmeter - ✔✔• Used to find a circuit problem with power on the circuit
• When checking for zero output voltage, a good starting point is to check the input with
a voltmeter
✔✔Ammeter - ✔✔• Used to find a circuit problem with power on the circuit
• Millimeters and micro ammeters measure very small rates of current flow
✔✔Ohmmeter - ✔✔• Used to find a circuit problem when power is removed from the
circuit
• Ohmmeters measured resistance
✔✔Oscilloscope - ✔✔• Measure and displays voltage (AC peak-to-peak) in waveforms
(output) of a wave generating circuit
✔✔Basic Troubleshooting Theory - ✔✔Continuity Check/Test
• Checks for the existence of a complete electrical system between two points
• Most of the time, a voltmeter or ohmmeter is used to test the continunity of a circuit
• Test should be made at each terminal of the circuit to isolate the problem
✔✔Steps in the Troubleshooting Process - ✔✔Isolate the problem
• Is the equipment being operated properly
• Is the problem ongoing
• Is the problem intermittent
• Is the problem worse during takeoff
• Does the problem exist while cruising
AND ANSWERS SCORED A+
✔✔Proton - ✔✔• Positively charged subatomic particles that exist within the nucleus of
all atoms
• Protons are not involved in the conduction of electricity
✔✔Resistance (R) - ✔✔• Electrical characteristic of a conductor
• Opposition that a circuit, component, or substance presents to flow of electricity
• Resistance is the force that opposes or slows down another force, drops voltage, and
consumes power
• Resistance is measured in ohms
• In mathematical problems ohms of resistance is expressed by symbol "R"
✔✔Scientific Notation - ✔✔• Short way of expressing a given number between 1 and 10
multiplied by 10 to the appropriate power
✔✔Static Electricity - ✔✔• Electrical charge that may be built up on a non-conductive
surface by friction
• Static electricity serves no useful purpose
✔✔Volt (V) - ✔✔• Basic unit of electrical pressure
• A volt is the amount of force required to cause one amp of current to flow through one
ohm or resistance
• Volt is often expressed by such terms as voltage, voltage drop, potential difference,
EMF, or IR drop
✔✔Watts (W) - ✔✔• Basic unit of power that is the product of voltage multiplied by
current
• One watt is power po
produced in a circuit that has one amp of current flowing under a pressure of one volt
✔✔Working Voltage - ✔✔• Maximum amount of DC voltage that can be safely applied
across a capacitor
✔✔Alternating Current (AC) - ✔✔• Flow of electrons that continuously changes it value
in magnitude and periodically reverses direction (sine-wave)
• Alternating current is much easier to produce in large quantities as compared to DC.
The time required for one cycle of AC to occur is called the period
✔✔Apparently Power - ✔✔• Product of effective voltage and effective current which is
expressed in Volt Amps (VA) rather than Watts (W) without reference to phase shift, if
any, between voltage and current
✔✔Capacitive Reactance (XC) - ✔✔• Opposition to current flow in a circuit
,• The affect that capacitance has on an AC circuit to lead voltage in phase (ICE)
• Values are given in ohms
✔✔Delta Wound - ✔✔• Windings arranged in the shape of a triangle
• For example, on a three-phase generator, motor, or transformer, two of the phase
windings are in series, across the third (phase) winding
✔✔Effective Voltage - ✔✔• Amount of AC that produces the same amount of heat as a
corresponding value of DC
• The effective voltage of AC is referred to as the RMS valve of AC
• Unless otherwise specified, all values of AC are considered effective values
✔✔Frequency - ✔✔• Number if cycles of AC completed in one second
• Frequecy is expressed in Hertz (Hz), 1 Hz = 1 cycle of AC/Sound
• The frequency of most AC used in aircraft applications is 400 Hz
✔✔Impedanc (Z) - ✔✔• Electrical characteristic of a conductor. Impedance is the total
opposition to the flow of AC in an electrical circuit ( resistance, capacitance, and
inductance)
• Values are given in ohms
✔✔Inductive Reactance (XL) - ✔✔• Opposition to current flow in a circuit
• The affect that inductance has on an AC circuit is termed inductive reactance
• Inductance causes current to lag voltage in phase (ELI). Values are given in ohms
✔✔Phase Angle - ✔✔• Angle between two similarly varying quantities (sine-waves)
• A phase angle is the difference in angle between two sinusoidally varying quantities
that have the same frequency
✔✔Polyphase - ✔✔• Production of two or more phases of AC, or of two or more
alternating voltages of the same frequency
• The most common type of polyphase uses three phases
✔✔Power Factor - ✔✔• Ratio of actual power dissipated in an electrical system to the
input power of volts multiplied by amps
• The power factor is the ratio of power dissipated over input
✔✔Rectifier - ✔✔• Electronic device that converts AC to DC
• For example, a set of semiconductor diodes connected
✔✔Root Mean Square (RMS) - ✔✔• Effective value of sine-wave alternating current
• The RMS value is .707 of the peak value
✔✔Sine-Wave - ✔✔• Alternating current wave form produced by a rotary generator
,• Sine-waves are values of voltage and current that start at zero and smoothly rise to a
peak value; the waves smoothly fall from a peak back to zero
• The waves then rise to a peak value in a negative direction and smoothly return to
zero
• One AC cycle is produced by 360 degrees of rotation
✔✔True Power - ✔✔• Power actually available in an AC circuit
• True power is the product of the circuit voltage and the current in phase with this
voltage
•Values are given in watts
✔✔Wye Wound - ✔✔• Windings arranged in the shape of a Y
• For example, on a three-phase generator or transformer, one end of each of the three
windings is connected to form a common point
✔✔Bridge Circuits - ✔✔• Contains four impedances that form a square
• Two diagonally opposite corners are connected to an input device
• The other two diagonally opposite corners are connected to an output device
✔✔Complex Circuit - ✔✔• Contains a combination of series and parallel circuits
✔✔Joules - ✔✔• International measure of energy expended in the kilogram, meter, and
second system of units
• Also known as a Newton-meter, a Joules is the amount of work done when a force of
one newton moves an object one meter along the direction of the force
✔✔Kirchhoff's Current Law (KCL) - ✔✔• Kirchhoff's current law states that "the
algebraic sum of the current flowing away from any point in an electrical circuit is equal
to the sum of the current flowing to that point"
✔✔Kirchhoff's Resistance Law (KRL) - ✔✔• Kirchhoff's Resistance Law states that "the
total resistance in a series circuit is the sum of the individual resistances or loads in the
circuit"
✔✔Kirchhoff's Voltage Law (KVL) - ✔✔• Kirchhoff's Voltage Law states that "the
algebraic song of all the voltage drops in any closed circuit is equal to zero"
✔✔Parallel Circuits - ✔✔• Contains more than one path for current
• Circuit components are connected directly across each other
• Current is divided between each branch in the circuit
✔✔Power - ✔✔• Product of applied voltage and current power in a DC circuit
• Product of applied voltage and the current in phase with the voltage in an AC circuit
✔✔Resistors in Series Circuits - ✔✔• Causes a reduction of current in one circuit
, ✔✔Resistors in Parallel Circuits - ✔✔• Causes a reduction of current in multiple circuits
✔✔Series Circuits - ✔✔• Contains only one path for current, making current common
through all components
• Series circuit components are connected end-to-end
✔✔Voltage Drop - ✔✔• Reduction in voltage caused by current flowing through a
resistor
• Voltage drop is called and IR (current X resistance) drop
✔✔Basic Troubleshooting Tools - ✔✔Multimeter
• Most versatile electrical measuring instrument used by aircraft technicians
• A multimeter has voltage, current, and resistance in an electrical circuit
• Each multimeter has a voltmeter, ammeter, and ohmmeter which are used to analyze
values in electrical circuits
✔✔Voltmeter - ✔✔• Used to find a circuit problem with power on the circuit
• When checking for zero output voltage, a good starting point is to check the input with
a voltmeter
✔✔Ammeter - ✔✔• Used to find a circuit problem with power on the circuit
• Millimeters and micro ammeters measure very small rates of current flow
✔✔Ohmmeter - ✔✔• Used to find a circuit problem when power is removed from the
circuit
• Ohmmeters measured resistance
✔✔Oscilloscope - ✔✔• Measure and displays voltage (AC peak-to-peak) in waveforms
(output) of a wave generating circuit
✔✔Basic Troubleshooting Theory - ✔✔Continuity Check/Test
• Checks for the existence of a complete electrical system between two points
• Most of the time, a voltmeter or ohmmeter is used to test the continunity of a circuit
• Test should be made at each terminal of the circuit to isolate the problem
✔✔Steps in the Troubleshooting Process - ✔✔Isolate the problem
• Is the equipment being operated properly
• Is the problem ongoing
• Is the problem intermittent
• Is the problem worse during takeoff
• Does the problem exist while cruising
