G5A02
What is reactance?
A. Opposition to the flow of direct current caused by resistance
B. Opposition to the flow of alternating current caused by capacitance or inductance
C. A property of ideal resistors in AC circuits
D. A large spark produced at switch contacts when an inductor is deenergized
G5A03
Which of the following causes opposition to the flow of alternating current in an inductor?
A. Conductance
B. Reluctance
C. Admittance
D. Reactance
G5A04
Which of the following causes opposition to the flow of alternating current in a capacitor?
A. Conductance
B. Reluctance
C. Reactance
D. Admittance
G5A05
How does a coil react to AC?
A. As the frequency of the applied AC increases, the reactance decreases
B. As the amplitude of the applied AC increases, the reactance increases
C. As the amplitude of the applied AC increases, the reactance decreases
D. As the frequency of the applied AC increases, the reactance increases
G5A06
How does a capacitor react to AC?
A. As the frequency of the applied AC increases, the reactance decreases
B. As the frequency of the applied AC increases, the reactance increases
C. As the amplitude of the applied AC increases, the reactance increases
D. As the amplitude of the applied AC increases, the reactance decreases
G5A07
What happens when the impedance of an electrical load is equal to the internal
impedance of the power source?
A. The source delivers minimum power to the load
B. The electrical load is shorted
C. No current can flow through the circuit
D. The source can deliver maximum power to the load
G5A08
Why is impedance matching important?
A. So the source can deliver maximum power to the load
B. So the load will draw minimum power from the source
C. To ensure that there is less resistance than reactance in the circuit
D. To ensure that the resistance and reactance in the circuit are equal
G5A09
What unit is used to measure reactance?
A. Farad
B. Ohm
C. Ampere
D. Siemens
G5A10
What unit is used to measure impedance?
A. Volt
B. Ohm
C. Ampere
D. Watt
G5A11
Why should core saturation of a conventional impedance matching
transformer be avoided?
A. Harmonics and distortion could result
B. Magnetic flux would increase with frequency
C. RF susceptance would increase
D. Temporary changes of the core permeability could result
G5A12
What is one reason to use an impedance matching transformer?
A. To reduce power dissipation in the transmitter
B. To maximize the transfer of power
C. To minimize SWR at the antenna
D. To minimize SWR in the transmission line
G5A13
Which of the following devices can be used for impedance matching at radio frequencies?
A. A transformer
B. A Pi-network
C. A length of transmission line
D. All of these choices are correct
G5A14
Which of the following describes one method of impedance
matching between two AC circuits?
A. Insert an LC network between the two circuits
B. Reduce the power output of the first circuit
C. Increase the power output of the first circuit
D. Insert a circulator between the two circuits
G5B02
How does the total current relate to the individual currents in
each branch of a parallel circuit?
A. It equals the average of each branch current
B. It decreases as more parallel branches are added to the circuit
C. It equals the sum of the currents through each branch
D. It is the sum of the reciprocal of each individual voltage drop
G5B03
How many watts of electrical power are used if 400 VDC is supplied to an 800-ohm load?
A. 0.5 watts
B. 200 watts
C. 400 watts
D. 3200 watts
G5B04
How many watts of electrical power are used by a 12-VDC light
bulb that draws 0.2 amperes?
A. 2.4 watts
B. 24 watts
C. 6 watts
D. 60 watts
G5B05
How many watts are being dissipated when a current of 7.0 milliamperes
flows through 1.25 kilohms?
A. Approximately 61 milliwatts
B. Approximately 39 milliwatts
C. Approximately 11 milliwatts
D. Approximately 9 milliwatts
G5B06
What is the output PEP from a transmitter if an oscilloscope
measures 200 volts peak-to-peak across a 50-ohm dummy
load connected to the transmitter output?
A. 1.4 watts
B. 100 watts
C. 353.5 watts
D. 400 watts
G5B07
Which measurement of an AC signal is equivalent to a DC voltage of the same value?
A. The peak-to-peak value
B. The peak value
C. The RMS value
D. The reciprocal of the RMS value
G5B08
What is the peak-to-peak voltage of a sine wave that has an RMS voltage of 120 volts?
A. 84.8 volts
B. 169.7 volts
C. 240.0 volts
D. 339.4 volts
G5B09
What is the RMS voltage of sine wave with a value of 17 volts peak?
A. 8.5 volts
B. 12 volts
C. 24 volts
D. 34 volts
G5B11
What is the ratio of peak envelope power to average power for an unmodulated carrier?
A. .707
B. 1.00
C. 1.414
D. 2.00
G5B12
What would be the voltage across a 50-ohm dummy load dissipating 1200 watts?
A. 173 volts
B. 245 volts
C. 346 volts
D. 692 volts
G5B13
What percentage of power loss would result from a transmission line loss of 1 dB?
A. 10.9 %
B. 12.2 %
C. 20.5 %
D. 25.9 %
G5B14 (B)
What is the output PEP from a transmitter if an oscilloscope
measures 500 volts peak-to-peak across a 50-ohm resistor
connected to the transmitter output?
A. 8.75 watts
B. 625 watts
C. 2500 watts
D. 5000 watts
G5B15
What is the output PEP of an unmodulated carrier if an average
reading wattmeter connected to the transmitter output indicates 1060 watts?
A. 530 watts
B. 1060 watts
C. 1500 watts
D. 2120 watts
G5C02
Where is the source of energy normally connected in a transformer?
A. To the secondary winding
B. To the primary winding
C. To the core
D. To the plates
G5C03
What is current in the primary winding of a transformer
called if no load is attached to the secondary?
A. Magnetizing current
B. Direct current
C. Excitation current
D. Stabilizing current
G5C04
What is the total resistance of three 100-ohm resistors in parallel?
A. .30 ohms
B. .33 ohms
C. 33.3 ohms
D. 300 ohms
G5C05
What is the value of each resistor if three equal value resistors in
parallel produce 50 ohms of resistance, and the same three resistors
in series produce 450 ohms?
A. 1500 ohms
B. 90 ohms
C. 150 ohms
D. 175 ohms
G5C06
What is the voltage across a 500-turn secondary winding in a
transformer if the 2250-turn primary is connected to 120 VAC?
A. 2370 volts
B. 540 volts
C. 26.7 volts
D. 5.9 volts
G5C07
What is the turns ratio of a transformer used to match an
audio amplifier having a 600-ohm output impedance to a
speaker having a 4-ohm impedance?
A. 12.2 to 1
B. 24.4 to 1
C. 150 to 1
D. 300 to 1
G5C08
What is the equivalent capacitance of two 5000 picofarad capacitors
and one 750 picofarad capacitor connected in parallel?
A. 576.9 picofarads
B. 1733 picofarads
C. 3583 picofarads
D. 10750 picofarads
G5C09
What is the capacitance of three 100 microfarad capacitors connected in series?
A. .30 microfarads
B. .33 microfarads
C. 33.3 microfarads
D. 300 microfarads
G5C10
What is the inductance of three 10 millihenry inductors connected in parallel?
A. .30 Henrys
B. 3.3 Henrys
C. 3.3 millihenrys
D. 30 millihenrys
G5C11
What is the inductance of a 20 millihenry inductor in series with a 50 millihenry inductor?
A. .07 millihenrys
B. 14.3 millihenrys
C. 70 millihenrys
D. 1000 millihenrys
G5C12
What is the capacitance of a 20 microfarad capacitor in series
with a 50 microfarad capacitor?
A. .07 microfarads
B. 14.3 microfarads
C. 70 microfarads
D. 1000 microfarads
G5C13
What component should be added to a capacitor in a circuit to
increase the circuit capacitance?
A. An inductor in series
B. A resistor in series
C. A capacitor in parallel
D. A capacitor in series
G5C14
What component should be added to an inductor in a
circuit to increase the circuit inductance?
A. A capacitor in series
B. A resistor in parallel
C. An inductor in parallel
D. An inductor in series
G5C15
What is the total resistance of a 10 ohm, a 20 ohm,
and a 50 ohm resistor in parallel?
A. 5.9 ohms
B. 0.17 ohms
C. 10000 ohms
D. 80 ohms
G5C16
What component should be added to an existing resistor in a
circuit to increase circuit resistance?
A. A resistor in parallel
B. A resistor in series
C. A capacitor in series
D. A capacitor in parallel