G7A: Power supplies; transmitters and receivers; filters; schematic symbols
G7A01:
What safety feature does a power-supply bleeder resistor provide?
It discharges the filter capacitors
It acts as a fuse for excess voltage
It removes shock hazards from the induction coils
It eliminates ground-loop current
G7A02:
What components are used in a power-supply filter network?
Capacitors and inductors
Diodes
Transformers and transistors
Quartz crystals
G7A03:
What should be the minimum peak-inverse-voltage rating of the rectifier in a full-wave power supply?
Double the normal peak output voltage of the power supply
One-quarter the normal output voltage of the power supply
Half the normal output voltage of the power supply
Equal to the normal output voltage of the power supply
G7A04:
What should be the approximate minimum peak-inverse-voltage rating of the rectifier in a half-wave power supply?
Two times the normal peak output voltage of the power supply
One-half the normal peak output voltage of the power supply
Half the normal output voltage of the power supply
Equal to the normal output voltage of the power supply
G7A05:
What should be the impedance of a low-pass filter as compared to the impedance of the transmission line into which it is inserted?
About the same
Substantially higher
Substantially lower
Twice the transmission line impedance
G7A06:
Which of the following might be used to process signals from the balanced modulator and send them to the mixer in a single-sideband phone transmitter?
Filter
Carrier oscillator
IF amplifier
RF amplifier
G7A07:
Which circuit is used to combine signals from the carrier oscillator and speech amplifier and send the result to the filter in a typical single-sideband phone transmitter?
Balanced modulator
Mixer
Detector
IF amplifier
G7A08:
What circuit is used to process signals from the RF amplifier and local oscillator and send the result to the IF filter in a superheterodyne receiver?
Mixer
Balanced modulator
IF amplifier
Detector
G7A09:
What circuit is used to process signals from the IF amplifier and BFO and send the result to the AF amplifier in a single-sideband phone superheterodyne receiver?
Product detector
RF oscillator
IF filter
Balanced modulator
G7A10:
What is an advantage of a crystal controlled transmitter?
Stable output frequency
Excellent modulation clarity
Ease of switching between bands
Ease of changing frequency
G7A11:
What is the simplest combination of stages that can be combined to implement a superheterodyne receiver?
HF oscillator, mixer, detector
RF amplifier, detector, audio amplifier
RF amplifier, mixer, if amplifier
HF oscillator, product detector, audio amplifier
G7A12:
What type of receiver is suitable for CW and SSB reception but does not require a mixer stage or an IF amplifier?
A direct conversion receiver
A super-regenerative receiver
A TRF receiver
A super-heterodyne receiver
G7A13:
What type of circuit is used in many FM receivers to convert signals coming from the IF amplifier to audio?
Discriminator
Product detector
Phase inverter
Mixer
G7A14:
Which of the following is a desirable characteristic for capacitors used to filter the DC output of a switching power supply?
Low equivalent series resistance
High equivalent series resistance
Low Temperature coefficient
High Temperature coefficient
G7A15:
Which of the following is an advantage of a switched-mode power supply as compared to a linear power supply?
High frequency operation allows the use of smaller components
Faster switching time makes higher output voltage possible
Fewer circuit components are required
All of these choices are correct
G7A16:
What portion of the AC cycle is converted to DC by a half-wave rectifier?
180 degrees
90 degrees
270 degrees
360 degrees
G7A17:
What portion of the AC cycle is converted to DC by a full-wave rectifier?
360 degrees
90 degrees
180 degrees
270 degrees
G7A18:
What is the output waveform of an unfiltered full-wave rectifier connected to a resistive load?
A series of DC pulses at twice the frequency of the AC input
A series of DC pulses at the same frequency as the AC input
A sine wave at half the frequency of the AC input
A steady DC voltage
G7A19:
Which symbol in figure G7-1 represents a fixed resistor?
Symbol 3
Symbol 2
Symbol 6
Symbol 12
G7A20:
Which symbol in figure G7-1 represents a single cell battery?
Symbol 13
Symbol 5
Symbol 12
Symbol 8
G7A21:
Which symbol in figure G7-1 represents a NPN transistor?
Symbol 4
Symbol 2
Symbol 10
Symbol 12
G7A22:
Which symbol in figure G7-1 represents a variable capacitor?
Symbol 5
Symbol 2
Symbol 11
Symbol 12
G7A23:
Which symbol in figure G7-1 represents a transformer?
Symbol 6
Symbol 4
Symbol 10
symbol 2
G7A24:
Which symbol in figure G7-1 represents a single pole switch?
Symbol 11
Symbol 2
Symbol 3
Symbol 12
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