Service Technician Conventional Exam Guide 2023 with
complete solution
Which of the following is the distance occupied by 1 hertz (Hz)?
Wavelength.
What is the return signal pass band frequency used in most of North America?
5-42 MHz.
What is the primary difference between coaxial express cable and coaxial
distribution cable in an HFC architecture?
Taps are installed on coaxial distribution cable and not on express cable.
Which testing device is the best to use to measure cable faults?
A time domain reflectometer (TDR).
Which of the following is used to define the waveform of an optical signal?
Wavelength.
What is the function of an interdiction unit?
An interdiction unit controls the level of service to the drop ports it contains.
Which of the following devices is an active device?
An addressable tap
The impedance of coaxial cable or a device is made up of the combined effects of
which three electrical properties?
Resistance, inductance, and capacitance.
When all other factors are equal, if the bonding wire and the cable connecting the
drop cable to consumer electronics are the same size, which should be shorter in
order to correctly bond the installation?
The bonding wire.
What is the definition of tap value?
The signal loss between the tap input port and the tap ports.
Alternating current is a current
That changes direction (or alternates) in the conductor each time the potential
difference applied to the ends of the conductor changes (or alternates) its polarity.
A simple AC generator containing a wire loop rotating between the poles of a
magnet produces AC voltage
Through magnetism and mechanical motion.
The amount of power lost as a result of conversion to heat in power transmission
lines
Is directly proportional to the amount of resistance present and to the square of the
amount of current.
To transmit AC power efficiently, what power line voltage-current combination
would deliver the same amount of power as 10 amps and 10,000 volts, but with
the least heat loss?
2 amps and 50,000 volts.
In a power transmission circuit, the transformer located near the user's home,
typically
Converts the high voltage, low current combination carried on the transmission lines to
a low voltage, high current combination for residential use.
,All true AC waveforms
Always are symmetrical about the horizontal axis.
The output voltage waveform generated by an AC generator during one complete
rotation of the generator's armature
Is called a sine wave.
The square wave and the sawtooth wave AC waveforms
Seem to decrease "instantly" from a maximum positive value to a maximum negative
value of voltage or current.
The polarity of a DC waveform
Does not change.
A fluctuating DC waveform
Can be identical to an AC waveform, except that the fluctuating DC waveform never
changes polarity.
One cycle
Is equal to one complete rotation of the armature of an AC generator.
What is the wavelength of one cycle of an AC waveform when: (1) the frequency
of the waveform is 80 Hz; (2) the speed of light is 300,000 kilometers per second;
and (3) the waveform has an amplitude of 5 volts?
3,750 km.
What is the time period of one cycle or wavelength of an AC waveform when the
frequency of the waveform is 50 Hz?
0.0200 seconds.
A phase angle
Is the amount of time, in degrees, it takes the waveform to change from the zero-degree
reference point to any other point on the waveform.
The amplitude of a waveform is defined as
The maximum level of either half-cycle of the waveform.
The peak value of a waveform
Is another name for the amplitude of the waveform.
What is the peak-to-peak value of an AC waveform when: (1) the frequency is 60
Hz; (2) the maximum negative value of the waveform is -4 volts; and (3) the
effective value of the waveform is 2.83 volts?
8.0 volts peak-to-peak.
Which of the following statements about instantaneous values is true?
The instantaneous value is the value of a single point on the AC waveform at a specific
moment, or instant, of time.
The average value
Is 3.18 volts for a waveform with a peak value of 5 volts.
What is the average value of an AC waveform that has an effective value of 8
volts?
7.2 volts.
How is an AC resistive circuit the same as a DC resistive circuit?
They have similar Ohm's law and power relationships, with certain exceptions.
Unless specified otherwise, I = E/R for an AC circuit is assumed to mean
The effective value of the current equals the effective value of the voltage divided by the
resistance.
, The basic power relationship "p(t) = e(t)i(t)"
Means the power at a specific instant equals the voltage at that same instant times the
current at that instant.
In resistive AC circuits,
The AC power waveform has two positive half-cycles and two positive peaks.
Eddy currents
Can cause a loss of power in an AC circuit.
The eddy-current losses in the conductors of an AC circuit are
Dependent on the frequency of the current flowing through the conductors.
Skin-effect losses
Are reduced by using multiple-strand conductors instead of a single, large diameter
conductor.
What is the value of the current when: (1) the effective voltage is 120 volts; (2) the
resistance of the source is 3 ohms; (3) the resistance of the conductors is 2
ohms; and (4) the resistance of the load is 5 ohms?
12.00 amperes.
What is the power consumed by the load when: (1) the voltage across the load is
7.5 volts; (2) the current flowing through the circuit is 0.25 amperes; and (3) the
resistance of the load is 30 ohms?
1.88 watts.
What is the power consumed by coaxial cable loop resistance when: (1) the
current of the coaxial cable circuit is 5 amperes; (2) the loop resistance of the
coaxial cable is .9345 ohms; and (3) the AC power source has an effective voltage
of 60 volts?
23.36 watts.
Induction
Is the production of an electromotive force (emf) in a conductor by changes in the
magnetic field around the conductor.
A henry is
Quite a large amount of inductance, so inductance in AC circuits is usually expressed
as a smaller value; in fractions of one henry.
Inductance is
The property of an electrical circuit or conductor that tends to resist changes in the
current flowing through the circuit or conductor.
Inductance in an inductor
Decreases when the number of turns around the core are decreased or when there is
an increase in the spacing between the turns around the core.
Inductors
Are rated in units of henrys.
Mutual inductance is
The property possessed by two inductors positioned so that the changing magnetic field
lines around one of the inductors encircle, or link, the turns of the other inductor and
induce an emf, or voltage, in that inductor.
A transformer
Is either an air-core or an iron-core transformer.
When the primary-to-secondary turns ratio in a transformer
complete solution
Which of the following is the distance occupied by 1 hertz (Hz)?
Wavelength.
What is the return signal pass band frequency used in most of North America?
5-42 MHz.
What is the primary difference between coaxial express cable and coaxial
distribution cable in an HFC architecture?
Taps are installed on coaxial distribution cable and not on express cable.
Which testing device is the best to use to measure cable faults?
A time domain reflectometer (TDR).
Which of the following is used to define the waveform of an optical signal?
Wavelength.
What is the function of an interdiction unit?
An interdiction unit controls the level of service to the drop ports it contains.
Which of the following devices is an active device?
An addressable tap
The impedance of coaxial cable or a device is made up of the combined effects of
which three electrical properties?
Resistance, inductance, and capacitance.
When all other factors are equal, if the bonding wire and the cable connecting the
drop cable to consumer electronics are the same size, which should be shorter in
order to correctly bond the installation?
The bonding wire.
What is the definition of tap value?
The signal loss between the tap input port and the tap ports.
Alternating current is a current
That changes direction (or alternates) in the conductor each time the potential
difference applied to the ends of the conductor changes (or alternates) its polarity.
A simple AC generator containing a wire loop rotating between the poles of a
magnet produces AC voltage
Through magnetism and mechanical motion.
The amount of power lost as a result of conversion to heat in power transmission
lines
Is directly proportional to the amount of resistance present and to the square of the
amount of current.
To transmit AC power efficiently, what power line voltage-current combination
would deliver the same amount of power as 10 amps and 10,000 volts, but with
the least heat loss?
2 amps and 50,000 volts.
In a power transmission circuit, the transformer located near the user's home,
typically
Converts the high voltage, low current combination carried on the transmission lines to
a low voltage, high current combination for residential use.
,All true AC waveforms
Always are symmetrical about the horizontal axis.
The output voltage waveform generated by an AC generator during one complete
rotation of the generator's armature
Is called a sine wave.
The square wave and the sawtooth wave AC waveforms
Seem to decrease "instantly" from a maximum positive value to a maximum negative
value of voltage or current.
The polarity of a DC waveform
Does not change.
A fluctuating DC waveform
Can be identical to an AC waveform, except that the fluctuating DC waveform never
changes polarity.
One cycle
Is equal to one complete rotation of the armature of an AC generator.
What is the wavelength of one cycle of an AC waveform when: (1) the frequency
of the waveform is 80 Hz; (2) the speed of light is 300,000 kilometers per second;
and (3) the waveform has an amplitude of 5 volts?
3,750 km.
What is the time period of one cycle or wavelength of an AC waveform when the
frequency of the waveform is 50 Hz?
0.0200 seconds.
A phase angle
Is the amount of time, in degrees, it takes the waveform to change from the zero-degree
reference point to any other point on the waveform.
The amplitude of a waveform is defined as
The maximum level of either half-cycle of the waveform.
The peak value of a waveform
Is another name for the amplitude of the waveform.
What is the peak-to-peak value of an AC waveform when: (1) the frequency is 60
Hz; (2) the maximum negative value of the waveform is -4 volts; and (3) the
effective value of the waveform is 2.83 volts?
8.0 volts peak-to-peak.
Which of the following statements about instantaneous values is true?
The instantaneous value is the value of a single point on the AC waveform at a specific
moment, or instant, of time.
The average value
Is 3.18 volts for a waveform with a peak value of 5 volts.
What is the average value of an AC waveform that has an effective value of 8
volts?
7.2 volts.
How is an AC resistive circuit the same as a DC resistive circuit?
They have similar Ohm's law and power relationships, with certain exceptions.
Unless specified otherwise, I = E/R for an AC circuit is assumed to mean
The effective value of the current equals the effective value of the voltage divided by the
resistance.
, The basic power relationship "p(t) = e(t)i(t)"
Means the power at a specific instant equals the voltage at that same instant times the
current at that instant.
In resistive AC circuits,
The AC power waveform has two positive half-cycles and two positive peaks.
Eddy currents
Can cause a loss of power in an AC circuit.
The eddy-current losses in the conductors of an AC circuit are
Dependent on the frequency of the current flowing through the conductors.
Skin-effect losses
Are reduced by using multiple-strand conductors instead of a single, large diameter
conductor.
What is the value of the current when: (1) the effective voltage is 120 volts; (2) the
resistance of the source is 3 ohms; (3) the resistance of the conductors is 2
ohms; and (4) the resistance of the load is 5 ohms?
12.00 amperes.
What is the power consumed by the load when: (1) the voltage across the load is
7.5 volts; (2) the current flowing through the circuit is 0.25 amperes; and (3) the
resistance of the load is 30 ohms?
1.88 watts.
What is the power consumed by coaxial cable loop resistance when: (1) the
current of the coaxial cable circuit is 5 amperes; (2) the loop resistance of the
coaxial cable is .9345 ohms; and (3) the AC power source has an effective voltage
of 60 volts?
23.36 watts.
Induction
Is the production of an electromotive force (emf) in a conductor by changes in the
magnetic field around the conductor.
A henry is
Quite a large amount of inductance, so inductance in AC circuits is usually expressed
as a smaller value; in fractions of one henry.
Inductance is
The property of an electrical circuit or conductor that tends to resist changes in the
current flowing through the circuit or conductor.
Inductance in an inductor
Decreases when the number of turns around the core are decreased or when there is
an increase in the spacing between the turns around the core.
Inductors
Are rated in units of henrys.
Mutual inductance is
The property possessed by two inductors positioned so that the changing magnetic field
lines around one of the inductors encircle, or link, the turns of the other inductor and
induce an emf, or voltage, in that inductor.
A transformer
Is either an air-core or an iron-core transformer.
When the primary-to-secondary turns ratio in a transformer
