home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Media Share 9
/
MEDIASHARE_09.ISO
/
hamradio
/
hamtest.zip
/
ELE4AF
< prev
next >
Wrap
Text File
|
1992-01-26
|
14KB
|
594 lines
FCC ADVANCED Exam Question Pool. Subelement 4AF.
Circuit Components. 6 Questions.
---------------------------------------------------
4AF 1.1 D
What is the schematic symbol for a semiconductor diode/rectifier? (Please
refer to Figure 4AF-1.1)
A. Symbol A
B. Symbol B
C. Symbol C
D. Symbol D
4AF 1.2 A
Structurally, what are the two main categories of semiconductor diodes?
A. Junction and point contact
B. Electrolytic and junction
C. Electrolytic and point contact
D. Vacuum and point contact
4AF 1.3 D
What is the schematic symbol for a Zener diode? (Please refer to Figure
4AF-1.3)
A. Symbol A
B. Symbol B
C. Symbol C
D. Symbol D
4AF 1.4 C
What are the two primary classifications of Zener diodes?
A. Hot carrier and tunnel
B. Varactor and rectifying
C. Voltage regulator and voltage reference
D. Forward and reversed biased
4AF 1.5 B
What is the principal characteristic of a Zener diode?
A. A constant current under conditions of varying voltage
B. A constant voltage under conditions of varying current
C. A negative resistance region
D. An internal capacitance that varies with the applied voltage
4AF 1.6 A
What is the range of voltage ratings available in Zener diodes?
A. 2.4 volts to 200 volts
B. 1.2 volts to 7 volts
C. 3 volts to 2000 volts
D. 1.2 volts to 5.6 volts
4AF 1.7 C
What is the schematic symbol for a tunnel diode? (Please refer to Figure
4AF-1.7)
A. Symbol A
B. Symbol B
C. Symbol C
D. Symbol D
4AF 1.8 C
What is the principal characteristic of a tunnel diode?
A. A high forward resistance
B. A very high PIV
C. A negative resistance region
D. A high forward current rating
4AF 1.9 C
What special type of diode is capable of both amplification and oscillation?
A. Point contact diodes
B. Zener diodes
C. Tunnel diodes
D. Junction diodes
4AF 1.10 D
What is the schematic symbol for a varactor diode? (Please refer to Figure
4AF-1.10)
A. Symbol A
B. Symbol B
C. Symbol C
D. Symbol D
4AF 1.11 A
What type of semiconductor diode varies its internal capacitance as the
voltage applied to its terminals varies?
A. A varactor diode
B. A tunnel diode
C. A silicon-controlled rectifier
D. A Zener diode
4AF 1.12 B
What is the principal characteristic of a varactor diode?
A. It has a constant voltage under conditions of varying current
B. Its internal capacitance varies with the applied voltage
C. It has a negative resistance region
D. It has a very high PIV
4AF 1.13 D
What is a common use of a varactor diode?
A. As a constant current source
B. As a constant voltage source
C. As a voltage controlled inductance
D. As a voltage controlled capacitance
4AF 1.14 D
What is a common use of a hot-carrier diode?
A. As balanced mixers in SSB generation
B. As a variable capacitance in an automatic frequency control circuit
C. As a constant voltage reference in a power supply
D. As VHF and UHF mixers and detectors
4AF 1.15 B
What limits the maximum forward current in a junction diode?
A. The peak inverse voltage
B. The junction temperature
C. The forward voltage
D. The back EMF
4AF 1.16 D
How are junction diodes rated?
A. Maximum forward current and capacitance
B. Maximum reverse current and PIV
C. Maximum reverse current and capacitance
D. Maximum forward current and PIV
4AF 1.17 C
What is a common use for point contact diodes?
A. As a constant current source
B. As a constant voltage source
C. As an RF detector
D. As a high voltage rectifier
4AF 1.18 D
What type of diode is made of a metal whisker touching a very small semi-
conductor die?
A. Zener diode
B. Varactor diode
C. Junction diode
D. Point contact diode
4AF 1.19 C
What is one common use for PIN diodes?
A. As a constant current source
B. As a constant voltage source
C. As an RF switch
D. As a high voltage rectifier
4AF 1.20 C
What special type of diode is often used in RF switches, attenuators, and
various types of phase shifting devices?
A. Tunnel diodes
B. Varactor diodes
C. PIN diodes
D. Junction diodes
4AF 2.1 C
What is the schematic symbol for a PNP transistor? (Please refer to Figure
4AF-2.1)
A. Symbol A
B. Symbol B
C. Symbol C
D. Symbol D
4AF 2.2 B
What is the schematic symbol for an NPN transistor? (Please refer to Figure
4AF-2.2)
A. Symbol A
B. Symbol B
C. Symbol C
D. Symbol D
4AF 2.3 B
What are the three terminals of a bipolar transistor?
A. Cathode, plate and grid
B. Base, collector and emitter
C. Gate, source and sink
D. Input, output and ground
4AF 2.4 C
What is the meaning of the term alpha with regard to bipolar transistors?
A. The change of collector current with respect to base current
B. The change of base current with respect to collector current
C. The change of collector current with respect to emitter current
D. The change of collector current with respect to gate current
4AF 2.5 C
What is the term used to express the ratio of change in DC collector current
to a change in emitter current in a bipolar transistor?
A. Gamma
B. Epsilon
C. Alpha
D. Beta
4AF 2.6 A
What is the meaning of the term beta with regard to bipolar transistors?
A. The change of collector current with respect to base current
B. The change of base current with respect to emitter current
C. The change of collector current with respect to emitter current
D. The change in base current with respect to gate current
4AF 2.7 B
What is the term used to express the ratio of change in the DC collector
current to a change in base current in a bipolar transistor?
A. Alpha
B. Beta
C. Gamma
D. Delta
4AF 2.8 B
What is the meaning of the term alpha cutoff frequency with regard to
bipolar transistors?
A. The practical lower frequency limit of a transistor in common emitter
configuration
B. The practical upper frequency limit of a transistor in common base
configuration
C. The practical lower frequency limit of a transistor in common base
configuration
D. The practical upper frequency limit of a transistor in common emitter
configuration
4AF 2.9 B
What is the term used to express that frequency at which the grounded base
current gain has decreased to 0.7 of the gain obtainable at 1 kHz in a
transistor?
A. Corner frequency
B. Alpha cutoff frequency
C. Beta cutoff frequency
D. Alpha rejection frequency
4AF 2.10 B
What is the meaning of the term beta cutoff frequency with regard to a
bipolar transistor?
A. That frequency at which the grounded base current gain has decreased to
0.7 of that obtainable at 1 kHz in a transistor
B. That frequency at which the grounded emitter current gain has decreased
to 0.7 of that obtainable at 1 kHz in a transistor
C. That frequency at which the grounded collector current gain has decreased
to 0.7 of that obtainable at 1 kHz in a transistor
D. That frequency at which the grounded gate current gain has decreased to
0.7 of that obtainable at 1 kHz in a transistor
4AF 2.11 A
What is the meaning of the term transition region with regard to
a transistor?
A. An area of low charge density around the P-N junction
B. The area of maximum P-type charge
C. The area of maximum N-type charge
D. The point where wire leads are connected to the P- or N-type material
4AF 2.12 A
What does it mean for a transistor to be fully saturated?
A. The collector current is at its maximum value
B. The collector current is at its minimum value
C. The transistor's Alpha is at its maximum value
D. The transistor's Beta is at its maximum value
4AF 2.13 C
What does it mean for a transistor to be cut off?
A. There is no base current
B. The transistor is at its operating point
C. No current flows from emitter to collector
D. Maximum current flows from emitter to collector
4AF 2.14 C
What is the schematic symbol for a unijunction transistor? (Please refer to
Figure 4AF-2.14)
A. Symbol A
B. Symbol B
C. Symbol C
D. Symbol D
4AF 2.15 A
What are the elements of a unijunction transistor?
A. Base 1, base 2 and emitter
B. Gate, cathode and anode
C. Gate, base 1 and base 2
D. Gate, source and sink
4AF 2.16 A
For best efficiency and stability, where on the load-line should a solid-
state power amplifier be operated?
A. Just below the saturation point
B. Just above the saturation point
C. At the saturation point
D. At 1.414 times the saturation point
4AF 2.17 B
What two elements widely used in semiconductor devices exhibit both metallic
and non-metallic characteristics?
A. Silicon and gold
B. Silicon and germanium
C. Galena and germanium
D. Galena and bismuth
4AF 3.1 D
What is the schematic symbol for a silicon controlled rectifier? (Please
refer to Figure 4AF-3.1)
A. Symbol A
B. Symbol B
C. Symbol C
D. Symbol D
4AF 3.2 A
What are the three terminals of an SCR?
A. Anode, cathode and gate
B. Gate, source and sink
C. Base, collector and emitter
D. Gate, base 1 and base 2
4AF 3.3 A
What are the two stable operating conditions of an SCR?
A. Conducting and nonconducting
B. Oscillating and quiescent
C. Forward conducting and reverse conducting
D. NPN conduction and PNP conduction
4AF 3.4 A
When an SCR is in the triggered or on condition, its electrical
characteristics are similar to what other solid-state device (as measured
between its cathode and anode)?
A. The junction diode
B. The tunnel diode
C. The hot-carrier diode
D. The varactor diode
4AF 3.5 D
Under what operating condition does an SCR exhibit electrical
characteristics similar to a forward-biased silicon rectifier?
A. During a switching transition
B. When it is used as a detector
C. When it is gated "off"
D. When it is gated "on"
4AF 3.6 A
What is the schematic symbol for a TRIAC? (Please refer to Figure 4AF-3.6)
A. Symbol A
B. Symbol B
C. Symbol C
D. Symbol D
4AF 3.7 A
What is the transistor called which is fabricated as two complementary SCRs
in parallel with a common gate terminal?
A. TRIAC
B. Bilateral SCR
C. Unijunction transistor
D. Field effect transistor
4AF 3.8 B
What are the three terminals of a TRIAC?
A. Emitter, base 1 and base 2
B. Gate, anode 1 and anode 2
C. Base, emitter and collector
D. Gate, source and sink
4AF 4.1 B
What is the schematic symbol for a light-emitting diode? (Please refer to
Figure 4AF-4.0)
A. Symbol A
B. Symbol B
C. Symbol C
D. Symbol D
4AF 4.2 C
What is the normal operating voltage and current for a light-emitting diode?
A. 60 volts and 20 mA
B. 5 volts and 50 mA
C. 1.7 volts and 20 mA
D. 0.7 volts and 60 mA
4AF 4.3 B
What type of bias is required for an LED to produce luminescence?
A. Reverse bias
B. Forward bias
C. Zero bias
D. Inductive bias
4AF 4.4 A
What are the advantages of using an LED?
A. Low power consumption and long life
B. High lumens per cm per cm and low power consumption
C. High lumens per cm per cm and low voltage requirement
D. A current flows when the device is exposed to a light source
4AF 4.5 D
What colors are available in LEDs?
A. Yellow, blue, red and brown
B. Red, violet, yellow and peach
C. Violet, blue, orange and red
D. Red, green, orange and yellow
4AF 4.6 C
What is the schematic symbol for a neon lamp? (Please refer to Figure 4AF-
4.5)
A. Symbol A
B. Symbol B
C. Symbol C
D. Symbol D
4AF 4.7 B
What type neon lamp is usually used in amateur radio work?
A. NE-1
B. NE-2
C. NE-3
D. NE-4
4AF 4.8 A
What is the DC starting voltage for an NE-2 neon lamp?
A. Approximately 67 volts
B. Approximately 5 volts
C. Approximately 5.6 volts
D. Approximately 110 volts
4AF 4.9 D
What is the AC starting voltage for an NE-2 neon lamp?
A. Approximately 110-V AC RMS
B. Approximately 5-V AC RMS
C. Approximately 5.6-V AC RMS
D. Approximately 48-V AC RMS
4AF 4.10 D
How can a neon lamp be used to check for the presence of RF?
A. A neon lamp will go out in the presence of RF
B. A neon lamp will change color in the presence of RF
C. A neon lamp will light only in the presence of very low frequency RF
D. A neon lamp will light in the presence of RF
4AF 5.1 B
What would be the bandwidth of a good crystal lattice band-pass filter for
a single-sideband phone emission?
A. 6 kHz at -6 dB
B. 2.1 kHz at -6 dB
C. 500 Hz at -6 dB
D. 15 kHz at -6 dB
4AF 5.2 C
What would be the bandwidth of a good crystal lattice band-pass filter for
a double-sideband phone emission?
A. 1 kHz at -6 dB
B. 500 Hz at -6 dB
C. 6 kHz at -6 dB
D. 15 kHz at -6 dB
4AF 5.3 D
What is a crystal lattice filter?
A. A power supply filter made with crisscrossed quartz crystals
B. An audio filter made with 4 quartz crystals at 1-kHz intervals
C. A filter with infinitely wide and shallow skirts made using quartz
crystals
D. A filter with narrow bandwidth and steep skirts made using quartz
crystals
4AF 5.4 D
What technique can be used to construct low cost, high performance crystal
lattice filters?
A. Splitting and tumbling
B. Tumbling and grinding
C. Etching and splitting
D. Etching and grinding
4AF 5.5 A
What determines the bandwidth and response shape in a crystal lattice
filter?
A. The relative frequencies of the individual crystals
B. The center frequency chosen for the filter
C. The amplitude of the RF stage preceding the filter
D. The amplitude of the signals passing through the filter
--------------------------------------------------
End of Subelement 4AF.