NCATT AET COMPREHENSIVE EXAM 2026 QUESTIONS AND
ANSWERS SCORED A+
✔✔Three-phase Rectifier - ✔✔• Commonly used to change AC electricity into DC
electricity
✔✔Band-pass - ✔✔• Passes certain bands of middle frequencies while attenuating high
and low frequencies through the use of resonant circuits
✔✔Band-reject - ✔✔• Attenuates a certain band of middle frequencies while passing the
high and low frequencies through the use of resonant circuits
✔✔Cutoff Frequency - ✔✔• Frequency at which attenuation starts to increase rapidly
✔✔Demodulation - ✔✔• Electronic filter that decreases the amplitude of some
frequencies relative to other frequencies
✔✔Detection - ✔✔• Another term for demodulation
✔✔Filtering - ✔✔• Frequency-sensitive filter circuits are designed to pass a certain
range of frequencies from the generator to the load device and reject all other
frequencies
• Filters are placed between the signal source (generator) and the load
• Filters act as frequency sensitive voltage dividers
✔✔High-pass - ✔✔• Passes high frequencies and attenuates low frequencies
✔✔Low-pass - ✔✔• Allows low frequencies to pass from the generator to the load
device and blocks, or attenuates, high frequencies
✔✔Tuning Circuit - ✔✔• Resonant electronic circuit containing both capacitance and
induction that can be adjusted to change the frequency
✔✔Use of Crystals - ✔✔• Material used in filters to assist in the rejection of unwanted
signals
• Filters contain thin slivers of quartz crystals that vibrate at a specific resonant
frequency when voltage is applied
• Crystal (called piezoelectric crystals) can be cut and ground for various frequencies
✔✔Crystal-controlled Oscillator - ✔✔• Electronic circuit that contains a piezoelectric
crystal
• Output frequency is determined by the resonant frequency of the piezoelectric crystal
in the oscillator
• A crystal-controlled oscillator produces a sine-wave
,✔✔Hartley Oscillator - ✔✔• Electronic circuit that uses a tapped coil in parallel with a
capacitor to control the AC frequency of a circuit
✔✔LC Tank Oscillator - ✔✔• Electronic circuit for communications receivers
• Produces useful power at two or three times the frequency of the fundamental pulse
rate
• Stores energy alternately in the inductor and the capacitor. This storage method
produces an output that is sinusoidal
✔✔Oscillator - ✔✔• Electronic circuit that converts DC into AC at predetermined
frequencies and amplitudes
• Without the amplifier, electronic oscillation would be quickly dampened out by the
resistance in the wiring of the circuit
• The primary purpose is to generate a repetitive waveform at a constant (peak to peak)
amplitude and specific frequency and to maintain this waveform within certain limits
✔✔Regenerative Feedback Path - ✔✔• Positive feedback
• A regenerative feedback path makes any amplifier an oscillator
✔✔Astable Multivibrator - ✔✔• Two conditions of temporary stability and no permanent
condition of stability
✔✔Bistable Multivibrator - ✔✔• Two transistors that alternate conducting. One transistor
conducts until an external pulse stops its conducting. Then, the other transistor takes
over conducting
✔✔Monostable Multivator - ✔✔• One permanent stable mode of operation
✔✔Transistor - ✔✔• Semiconductor devices that have three or more electrodes
• Transistors are used for switches and amplifiers
✔✔Proper Use and Installation - ✔✔• Handle a device safely and properly
• Use industry standards to install a device correctly
✔✔Schematic Diagram and Symbols - ✔✔• Electric or fluid power system graphical
presentation • Components of the system are represented by symbols, not pictures or
drawings
• A schematic diagram is used mainly for troubleshooting a system or device
✔✔Zener Diodes - ✔✔• Special application diode in which electricity is conducted under
certain voltage conditions
• The zener diode's primary purpose is to regulate voltage
✔✔Base Current - ✔✔• Electrode between the emitter and the collector
, • The base controls the amount of current passed
✔✔Bipolar Transistors - ✔✔• NPN Transistor—Three-element semiconductor formed by
placing a lightly doped, very thin region of P-type silicon or germanium between two
regions of N-type material which affects current
• PNP Transistor—Three-element semiconductor formed by placing a lightly doped,
very thin region of N-type silicon or germanium between two regions of P-type material
which affects current
• Polarity of Connections—NPN and PNP transistors are not interchangeable because
of their opposite polarities
✔✔Collector Base Junction - ✔✔• Must be reverse-biased for a transistor to conduct
current
✔✔Collector Current - ✔✔• Electrode from which conventional current leaves the
transistor
• The collector collects the current
✔✔Emitter Base Junction - ✔✔• Must be forward-biased for a transistor to conduct
current
✔✔Emitter Current - ✔✔• Electrode that compares with the cathode in an electron tube
• The emitter emits the current carriers
✔✔Junction - ✔✔• Point at which two materials are in contact with each other
✔✔Binary Digit (bit) - ✔✔• Each zero or one is a binary number
✔✔Binary Numbering System (Binary Notation) - ✔✔• Mathematical computation based
on powers of two
• The binary numbering system is composed of two digits (1 and 0)
• Binary notation operates in Base 2
• Each digit in a binary number represents two bits
✔✔Byte - ✔✔• Consists of eight bits
✔✔Conversions - ✔✔• Mathematical ways to express digital numbering systems
• A decimal number may be converted to its binary equivalent by sequentially dividing
the number by 2 and recording each remainder
✔✔Decimal Numbering System - ✔✔• Uses numbers 0 - 9
• The decimal numbering system operates in Base 10
✔✔Octal Numbering System (Octal Notation) - ✔✔• Mathematical computation based
on powers of eight
ANSWERS SCORED A+
✔✔Three-phase Rectifier - ✔✔• Commonly used to change AC electricity into DC
electricity
✔✔Band-pass - ✔✔• Passes certain bands of middle frequencies while attenuating high
and low frequencies through the use of resonant circuits
✔✔Band-reject - ✔✔• Attenuates a certain band of middle frequencies while passing the
high and low frequencies through the use of resonant circuits
✔✔Cutoff Frequency - ✔✔• Frequency at which attenuation starts to increase rapidly
✔✔Demodulation - ✔✔• Electronic filter that decreases the amplitude of some
frequencies relative to other frequencies
✔✔Detection - ✔✔• Another term for demodulation
✔✔Filtering - ✔✔• Frequency-sensitive filter circuits are designed to pass a certain
range of frequencies from the generator to the load device and reject all other
frequencies
• Filters are placed between the signal source (generator) and the load
• Filters act as frequency sensitive voltage dividers
✔✔High-pass - ✔✔• Passes high frequencies and attenuates low frequencies
✔✔Low-pass - ✔✔• Allows low frequencies to pass from the generator to the load
device and blocks, or attenuates, high frequencies
✔✔Tuning Circuit - ✔✔• Resonant electronic circuit containing both capacitance and
induction that can be adjusted to change the frequency
✔✔Use of Crystals - ✔✔• Material used in filters to assist in the rejection of unwanted
signals
• Filters contain thin slivers of quartz crystals that vibrate at a specific resonant
frequency when voltage is applied
• Crystal (called piezoelectric crystals) can be cut and ground for various frequencies
✔✔Crystal-controlled Oscillator - ✔✔• Electronic circuit that contains a piezoelectric
crystal
• Output frequency is determined by the resonant frequency of the piezoelectric crystal
in the oscillator
• A crystal-controlled oscillator produces a sine-wave
,✔✔Hartley Oscillator - ✔✔• Electronic circuit that uses a tapped coil in parallel with a
capacitor to control the AC frequency of a circuit
✔✔LC Tank Oscillator - ✔✔• Electronic circuit for communications receivers
• Produces useful power at two or three times the frequency of the fundamental pulse
rate
• Stores energy alternately in the inductor and the capacitor. This storage method
produces an output that is sinusoidal
✔✔Oscillator - ✔✔• Electronic circuit that converts DC into AC at predetermined
frequencies and amplitudes
• Without the amplifier, electronic oscillation would be quickly dampened out by the
resistance in the wiring of the circuit
• The primary purpose is to generate a repetitive waveform at a constant (peak to peak)
amplitude and specific frequency and to maintain this waveform within certain limits
✔✔Regenerative Feedback Path - ✔✔• Positive feedback
• A regenerative feedback path makes any amplifier an oscillator
✔✔Astable Multivibrator - ✔✔• Two conditions of temporary stability and no permanent
condition of stability
✔✔Bistable Multivibrator - ✔✔• Two transistors that alternate conducting. One transistor
conducts until an external pulse stops its conducting. Then, the other transistor takes
over conducting
✔✔Monostable Multivator - ✔✔• One permanent stable mode of operation
✔✔Transistor - ✔✔• Semiconductor devices that have three or more electrodes
• Transistors are used for switches and amplifiers
✔✔Proper Use and Installation - ✔✔• Handle a device safely and properly
• Use industry standards to install a device correctly
✔✔Schematic Diagram and Symbols - ✔✔• Electric or fluid power system graphical
presentation • Components of the system are represented by symbols, not pictures or
drawings
• A schematic diagram is used mainly for troubleshooting a system or device
✔✔Zener Diodes - ✔✔• Special application diode in which electricity is conducted under
certain voltage conditions
• The zener diode's primary purpose is to regulate voltage
✔✔Base Current - ✔✔• Electrode between the emitter and the collector
, • The base controls the amount of current passed
✔✔Bipolar Transistors - ✔✔• NPN Transistor—Three-element semiconductor formed by
placing a lightly doped, very thin region of P-type silicon or germanium between two
regions of N-type material which affects current
• PNP Transistor—Three-element semiconductor formed by placing a lightly doped,
very thin region of N-type silicon or germanium between two regions of P-type material
which affects current
• Polarity of Connections—NPN and PNP transistors are not interchangeable because
of their opposite polarities
✔✔Collector Base Junction - ✔✔• Must be reverse-biased for a transistor to conduct
current
✔✔Collector Current - ✔✔• Electrode from which conventional current leaves the
transistor
• The collector collects the current
✔✔Emitter Base Junction - ✔✔• Must be forward-biased for a transistor to conduct
current
✔✔Emitter Current - ✔✔• Electrode that compares with the cathode in an electron tube
• The emitter emits the current carriers
✔✔Junction - ✔✔• Point at which two materials are in contact with each other
✔✔Binary Digit (bit) - ✔✔• Each zero or one is a binary number
✔✔Binary Numbering System (Binary Notation) - ✔✔• Mathematical computation based
on powers of two
• The binary numbering system is composed of two digits (1 and 0)
• Binary notation operates in Base 2
• Each digit in a binary number represents two bits
✔✔Byte - ✔✔• Consists of eight bits
✔✔Conversions - ✔✔• Mathematical ways to express digital numbering systems
• A decimal number may be converted to its binary equivalent by sequentially dividing
the number by 2 and recording each remainder
✔✔Decimal Numbering System - ✔✔• Uses numbers 0 - 9
• The decimal numbering system operates in Base 10
✔✔Octal Numbering System (Octal Notation) - ✔✔• Mathematical computation based
on powers of eight
