G7 Questions
35 questions in this subelement. Click any question ID for more details.
Answer: C
Which of the following components are used in a power supply filter network?
ADiodes
BTransformers and transducers
CCapacitors and inductors
DAll these choices are correct
Answer: A
Which type of rectifier circuit uses two diodes and a center-tapped transformer?
AFull-wave
BFull-wave bridge
CHalf-wave
DSynchronous
Answer: A
What is characteristic of a half-wave rectifier in a power supply?
AOnly one diode is required
BThe ripple frequency is twice that of a full-wave rectifier
CMore current can be drawn from the half-wave rectifier
DThe output voltage is two times the peak input voltage
Answer: B
What portion of the AC cycle is converted to DC by a half-wave rectifier?
A90 degrees
B180 degrees
C270 degrees
D360 degrees
Answer: D
What portion of the AC cycle is converted to DC by a full-wave rectifier?
A90 degrees
B180 degrees
C270 degrees
D360 degrees
Answer: A
What is the output waveform of an unfiltered full-wave rectifier connected to a resistive load?
AA series of DC pulses at twice the frequency of the AC input
BA series of DC pulses at the same frequency as the AC input
CA sine wave at half the frequency of the AC input
DA steady DC voltage
Answer: C
Which of the following is characteristic of a switchmode power supply as compared to a linear power supply?
AFaster switching time makes higher output voltage possible
BFewer circuit components are required
CHigh-frequency operation allows the use of smaller components
DInherently more stable
Answer: C
Which symbol in figure G7-1 represents a field effect transistor?
ASymbol 2
BSymbol 5
CSymbol 1
DSymbol 4
Answer: D
Which symbol in figure G7-1 represents a Zener diode?
ASymbol 4
BSymbol 1
CSymbol 11
DSymbol 5
Answer: B
Which symbol in figure G7-1 represents an NPN junction transistor?
ASymbol 1
BSymbol 2
CSymbol 7
DSymbol 11
Answer: C
Which symbol in Figure G7-1 represents a solid core transformer?
ASymbol 4
BSymbol 7
CSymbol 6
DSymbol 1
Answer: A
Which symbol in Figure G7-1 represents a tapped inductor?
ASymbol 7
BSymbol 11
CSymbol 6
DSymbol 1
Answer: D
Which of these classes of amplifiers has the highest efficiency?
AClass A
BClass B
CClass AB
DClass C
Answer: B
Which of the following describes the function of a two-input AND gate?
AOutput is high when either or both inputs are low
BOutput is high only when both inputs are high
COutput is low when either or both inputs are high
DOutput is low only when both inputs are high
Answer: A
In a Class A amplifier, what percentage of the time does the amplifying device conduct?
A100%
BMore than 50% but less than 100%
C50%
DLess than 50%
Answer: A
What is a shift register?
AA clocked array of circuits that passes data in steps along the array
BAn array of operational amplifiers used for tri-state arithmetic operations
CA digital mixer
DAn analog mixer
Answer: D
Which of the following are basic components of a sine wave oscillator?
AAn amplifier and a divider
BA frequency multiplier and a mixer
CA circulator and a filter operating in a feed-forward loop
DA filter and an amplifier operating in a feedback loop
Answer: B
How is the efficiency of an RF power amplifier determined?
ADivide the DC input power by the DC output power
BDivide the RF output power by the DC input power
CMultiply the RF input power by the reciprocal of the RF output power
DAdd the RF input power to the DC output power
Answer: C
What determines the frequency of an LC oscillator?
AThe number of stages in the counter
BThe number of stages in the divider
CThe inductance and capacitance in the tank circuit
DThe time delay of the lag circuit
Answer: B
Which of the following describes a linear amplifier?
AAny RF power amplifier used in conjunction with an amateur transceiver
BAn amplifier in which the output preserves the input waveform
CA Class C high efficiency amplifier
DAn amplifier used as a frequency multiplier
Answer: B
For which of the following modes is a Class C power stage appropriate for amplifying a modulated signal?
ASSB
BFM
CAM
DAll these choices are correct
Answer: D
What output is produced by a balanced modulator?
AFrequency modulated RF
BAudio with equalized frequency response
CAudio extracted from the modulation signal
DDouble-sideband modulated RF
Answer: B
What is one reason to use an impedance matching transformer at a transmitter output?
ATo minimize transmitter power output
BTo present the desired impedance to the transmitter and feed line
CTo reduce power supply ripple
DTo minimize radiation resistance
Answer: D
How is a product detector used?
AUsed in test gear to detect spurious mixing products
BUsed in a transmitter to perform frequency multiplication
CUsed in an FM receiver to filter out unwanted sidebands
DUsed in a single sideband receiver to extract the modulated signal
Answer: D
Which of the following is characteristic of a direct digital synthesizer (DDS)?
AExtremely narrow tuning range
BRelatively high-power output
CPure sine wave output
DVariable output frequency with the stability of a crystal oscillator
Answer: A
Which of the following is an advantage of a digital signal processing (DSP) filter compared to an analog filter?
AA wide range of filter bandwidths and shapes can be created
BFewer digital components are required
CMixing products are greatly reduced
DThe DSP filter is much more effective at VHF frequencies
Answer: A
What term specifies a filter’s attenuation inside its passband?
AInsertion loss
BReturn loss
CQ
DUltimate rejection
Answer: D
Which parameter affects receiver sensitivity?
AInput amplifier gain
BDemodulator stage bandwidth
CInput amplifier noise figure
DAll these choices are correct
Answer: B
What is the phase difference between the I and Q RF signals that software-defined radio (SDR) equipment uses for modulation and demodulation?
AZero
B90 degrees
C180 degrees
D45 degrees
Answer: B
What is an advantage of using I-Q modulation with software-defined radios (SDRs)?
AThe need for high resolution analog-to-digital converters is eliminated
BAll types of modulation can be created with appropriate processing
CMinimum detectible signal level is reduced
DAutomatic conversion of the signal from digital to analog
Answer: D
Which of these functions is performed by software in a software-defined radio (SDR)?
AFiltering
BDetection
CModulation
DAll these choices are correct
Answer: C
What is the frequency above which a low-pass filter’s output power is less than half the input power?
ANotch frequency
BNeper frequency
CCutoff frequency
DRolloff frequency
Answer: D
What term specifies a filter’s maximum ability to reject signals outside its passband?
ANotch depth
BRolloff
CInsertion loss
DUltimate rejection
Answer: A
The bandwidth of a band-pass filter is measured between what two frequencies?
AUpper and lower half-power
BCutoff and rolloff
CPole and zero
DImage and harmonic