Frenzel Communications Electronics Self Test / Exam Chapter 14


Self-Test 
& Supply the missing word(s) in each statement.
    Choose the letter that best answers each question. 
1.        Images are converted into electrical signals by a process of _____ with a light source and photosensitive detector.
2.        The most common transmission medium for fax signals is _____.
3.        Standards for fax transmission are set by the _____.
4.        The modulation method used in group 1 machines was PM with black = _____ Hz and white= _____ Hz.
5.        Vestigial sideband AM is used in group _____ machines.
6.        The photosensitive device used in most modern fax machines to convert a scanned line into an analog signal is a(n)
7.        Most modem fax machines are of the group _____ type.
8.        To ensure compatibility between sending and receiving fax machines, control logic carries out the process of _____ by audio tones prior to transmission.
9.        The most commonly used type of printer in a fax machine is a(n) _____ printer.
10.     The upper speed limit of a G3 fax machine over telephone lines is _____ baud.
11.     The resolution of a G3 fax machine is typically _____ lines per-inch.
12.     The two modulation techniques used in G3 machines are _____.
13.     A fax transmission is usually _____ (full, halt) duplex.
14.     The speed and resolution of group 4 fax transmissions are _____ kbits/s and _____ lines per inch.
15.     True or false. Fax can transmit photos and drawings as well as printed text.
16.     True or false. Fax signals may not be transmitted by radio.
17.     True or false. Group 4 transmission do not use the standard telephone lines.
18.     The area to be served by a cellular telephone system is divided into adjacent _____.
19.     The master control station for a group of cells is called the _____.
20.     Name two reasons why there are more channels, available in cellular systems than in older mobile telephone systems.
21.     The number of channels available is _____.
22.     True or false. Cellular telephone radios operate full duplex.
23.     The type of modulation used in a cellular radio is _____.
24.     The maximum power output of a cellular transmitter is _____ W.
25.     The transmit frequency range is _____ to _____ MHz.
26.     The receive frequency range is _____ to _____ MHz.
27.     Channels pacing is _____ kHz.
28.     Separation between send and receive frequencies is _____ MHz.
29.     Transmit and receive frequencies are determined by a(n) _____.
30.     Common first IFs are _____ and _____ MHz. Common second IFs are _____ and _____ MHz.
31.     The APC circuit causes the transmitter power to _____ based on an input control signal from the MTSO.
32.     A _____ allows the transmitter and receiver to share an antenna.
33.     True or false. The transmit and receive channel is selected by the operator. .
34.     The source of the frequency divider ratios in the frequency synthesizer PLLs is the _____.
35.     Name two signals that are transmitted back to the cell site and are monitored by the MTSO.
36.     Name three conditions in the transceiver that are controlled by the MTSO.
37.     A dc signal derived from the demodulator and used to tell the MTSO about received signal strength is called the _____.
38.     A receiver has a first IF of 82.2 MHz. The second IF is 456 kHz. The LO frequency on the second mixer is _____ MHz.
39.     The section of the cellular transceiver that interprets the serial digital data from the cell site and MTSO is the _____ unit.
40.     How many microprocessors do most cellular transceivers contain?
41.     The handset is part of the _____ section of the transceiver.
42.     When the speed of radio signals is known, radar can be used to determine the _____ of a target.
43.     An echo is the _____ from a target.
44.     The directivity of the radar antenna determines the _____ of a target.
45.     The speed of a radar signal is _____ ms/nmi.
46.     The elapsed time between radiating a radar signal and receiving its echo is 43.2 ms. The target distance in nautical miles is _____.
47.     If a target is 1000 yd away, the time period between the transmission of the signal and receipt of the echo is _____ ms.
48.     One nautical mile is equal to _____ statute miles.
49.     For optimum reflection from a target, the wavelength of the radar signal should be _____ compared to the size of the target.
50.     Radars operate in the _____ frequency range.
51.     True or false. Both the transmitter and receiver in a radar share the same antenna.
52.     The two main types of radar are _____.
53.     A frequency shift of sound, radio, or light waves that occurs as the result of the relative motion between objects is called the _____ effect.
54.     A CW radar operates at a frequency of 14 GHz. A frequency shift of 25 kHz is produced by a moving target. Its speed is _____ mi/h.
55.     True or false. Distance can be measured with constant-frequency CW radar.
56.     A waveguide assembly that lets the transmitter and receiver share an antenna is called a(n) _____.
57.     The most commonly used component in a radar transmitter is a(n) _____ tube.
58.     Both TR and ATR tubes incorporate a(n) _____.
59.     The output display in a radar is usually a(n) _____.
60.     A display that sweeps outward from the center of the screen while rotating is known as a(n) _____.
61.     A radar using multiple antennas to shape the beam width and automatically adjust directivity is known as a(n) _____ radar.
62.     The bandwidth of a standard TV signal is _____ MHz.
63.     The video carrier is _____ modulated and the sound carrier is _____ modulated.
64.     The spacing between the sound and picture carriers is _____ MHz.
65.     TV stations operate in the _____ and _____ regions of the spectrum.
66.     The brightness signal produced by a video camera is called the _____ or _____ signal.
67.     Two electronic imaging devices used in TV cameras to produce video signals are the _____  and the _____.
68.     The process that breaks up a picture or scene into serially transmitted signals is called _____.
69.     The three basic colors of light which can be used to produce any other color are _____ , _____, and _____.
70.     A NTSC TV picture or one frame of video is composed of _____ scan lines.
71.     A field consists of _____ scan lines.
72.     The field and frame rates are _____ and _____ Hz respectively.
73.     The time needed to scan one horizontal line in a color TV set is _____.
74.     To keep the picture at the receiver in step with the transmitted signal, _____ are added to the video.
75.     The circuit that lets the picture and sound transmitters use the same antenna is the _____.
76.     The color in a scene is generated by a camera that develops three signals that represent the amount of _____, _____, and _____ light present along every scan line.
77.     The red, greed, and blue color signals are combined in a resistive matrix to produce the two color signals called _____ and _____.
78.     The two color signals are fed to _____ circuits that produce _____ modulation.
79.     The color signals modulate a subcarrier with a frequency of _____.
80.     The characteristic of the composite color signal that tells the receiver the transmitted color is its _____.
81.     The _____ signal can be formed by adding the color signals in the following proportion:  0.11B +0.59G + O.3R.
82.     Channel selection in the tuner is accomplished by using a(n) _____ for a local oscillator.
83.     The _____ portion of a modern TV set uses digitally coded infrared signals for channel, volume, and other changes.
84.     A channel 33 UHF TV station has a picture carrier frequency of 585.25 MHz. The sound carrier frequency is _____.
85.     The frequency of the video signal representing fine detail along a scan line can have a frequency up to about _____.
86.     The TV receiver sound IF is _____ MHz, and the picture IF is _____ MHz.
87.     The name of the special filter that provides most of the adjacent channel selectivity for the TV receiver is _____.
88.     Spectrum space is conserved by using _____ modulation for the video in a TV signal.
89.     In the TV receiver, the picture and sound IF beat together to form the sound IF of _____ MHz.
90.     Two common sound demodulators in TV receivers are the _____ and the _____.
91.     The composite color signal is demodulated in two _____ demodulator circuits fed with quadrature 3.58-MHz signals from a subcarrier oscillator.
92.     The. 3.58-MHz subcarrier oscillator in the receiver is phase- and frequency-synchronized to the _____ signal transmitted along with the horizontal sync pulses.
93.     The _____ circuit strips the horizontal sync pulses from the video detector output.
94.     The horizontal sync pulses synchronize in internal sweep oscillator to a frequency of _____ Hz.
95.     The vertical sweep oscillator is synchronized to a frequency of _____ Hz by as sync pulse derived by _____ the horizontal sync pulses occurring during the vertical blanking interval.
96.     The horizontal and vertical sweep signals are currents with the shape of a(n) _____.
97.     The sweep signals are applied to the _____ assembly around the neck of the picture tube.
98.     The electron beam is generated by the _____ element in the picture tube and focused into a narrow beam by the
99.     The electron beam is deflected and swept across the face of the picture tube by _____ generated by the _____.
100.  A color CRT contains _____ electron guns to excite the color dot triads on the face of the tube.
101.  The _____ circuits ensure that the electron beams strike the correct color dots.
102.  The _____ stage is used as switching power supply to develop the HV required to operate the picture tube.
103.  The transformer used to step up and step down the horizontal sync pulses is called the _____.
104.  The name given to the cable TV station that collects and distributes the cable signals is _____.
105.  The, main cables used to distribute the TV signals to subscribers are called the _____ and _____.
106.  The coaxial cables that feed individual houses are called _____ and typically have a characteristic impedance of _____ ohms.
107.  The cable TV station may change the TV signal frequency by translating it to another frequency by using a _____.
108.  Cable attenuation occurring during distribution is overcome by using _____.
109.  The cable box used by the subscriber contains two, main circuits, the _____ and the _____.
110.  The output of the cable box is a TV signal on channel _____ or _____ that is connected to the _____ of the TV set.
Four advantages of cable TV are _____, _____, _____, and _____.

Frenzel Communications Electronics Self Test / Exam Chapter 13


Self-Test 
& Supply the missing word(s) in each statement.
    Choose the letter that best answers each question. 
1.        Fiber-optic cables carry _____ rather than electrical signals.
2.        The three main types of information carried by fiber optic-cables are _____, _____, and _____.
3.        The major use of fiber-optic cables is in _____.
4.        Fiber-optic cables are made of _____ or _____.
5.        The main benefit of fiber-optic cable over electric cable is its _____.
6.        True or false. Fiber-optic cable has more loss than electric cable over long distances.
7.        True or false. Fiber-optic cable is smaller, lighter, and stronger than electric cable.
8.        List the two main disadvantages of fiber optic cable.
9.        The two most commonly used light sources in fiber-optic systems are _____.
10.     Voice and video signals are converted into before being transmitted by a light beam.
11.     The device that converts the light pulses into an electrical signal is a(n) _____.
12.     Regenerative units called _____ are often used to compensate for signal attenuation over long distances.
13.     Light is a type of _____ radiation.
14.     A fiber-optic cable can be viewed as a light _____.
15.     Light travels in a
a.        Circle
b.        Straight line
c.        Curve
d.        Random way
16.     The wavelength of light is usually expressed in _____ or _____.
17.     The lowest-frequency visible light is
a.        Red
b.        Violet
18.     A micrometer, or micron, is a length of _____ of a _____.
19.     The wavelength range of visible light is _____ to _____ nm.
20.     Infrared light has a wavelength that is
a.        Less than 400 nm
b.        More than 700 nm
c.        Less than 700 nm
21.     The optical spectrum is made up of what three parts?
22.     The speed of light in air is _____ m/s or _____ mi/s.
23.     True or false. The speed of light is slower in glass or water than it is in air.
24.     The number that tells how fast light travels in a medium compared to air is the _____ of _____.
25.     Light beams can be bounced or their direction can be changed by _____ with a(n) _____.
26.     The bending of light rays due to speed changes when moving from one medium to another is called _____.
27.     If a light ray strikes a mirror at an angle of 30° from the normal, it is reflected at an angle of _____ ° from the normal.
28.     When the angle of refraction is 90° to the normal, the ray travels along the _____ between the two media. Therefore, the incident ray strikes the surface at the _____ angle.
29.     When the incident ray strikes the interface at an angle greater than the critical angle, _____ occurs.
30.     The critical angle depends upon the value of the _____ of _____.
31.     Which material has the best optical characteristics and lowest loss?
a.        Plastic
b.        Glass
c.        they are equal
32.     The core is protected by the _____.
33.     In PCS cable, the core is _____ and the cladding is _____.
34.     The index of refraction is highest in the
a.        Core
b.        Cladding
35.     List the three main types of fiber-optic cable.
36.     Stretching of the light pulse is called _____.
37.     List the two types of cable in which light pulse stretching occurs.
38.     High-frequency pulses can be best transmitted over _____ cable.
39.     Pulse stretching causes the information capacity of a cable to
a.        Increase
b.        Decrease
40.     Graded index means that the _____ of _____ of the core varies over its cross section
41.     Single-mode step-index cable has a Core diameter in the range of
a.        100 to 1000 mm
b.        50 to 100 mm
c.        2 to 15 mm
42.     A _____ is applied over the cladding to protect against moisture, damage, etc.
43.     A common protective layer in a cable is made of _____ mesh.
44.     Fiber-optic cables are available with the following number of cores: _____.
45.     Light loss in a cable is called _____.
46.     Light loss is caused by _____.
47.     Light loss is measured in _____ per_____.
48.     A cable with a loss of 5 dB will have _____ percent of the input appear at the output (see Fig. 13-19). (page 365-Frenzel)
49.     True or false. A kilometer is longer than a mile.
50.     Which cable length will have the least attenuation?
a.        40 ft
b.        120 ft
c.        1780 ft
d.        1 km
51.     Three cables with attenuations of 9, 22, and 45 dB are spliced together. The total attenuation is _____ dB.
52.     True or false. Fiber-optic cables may be spliced.
53.     To conveniently link and attach fiber-optic cables to one another and related equipment, _____ are used.
54.     The two most common light sources used in fiber-optic transmitters are _____.
55.     The most popular light wavelength is _____ mm because fiber-optic cable attenuation is lowest at that wavelength.
56.     True or false. The light from a 1.55mm LED is visible.
57.     Usually LEDs are made of _____.
58.     Single frequency light is called _____.
59.     The condition of all emitted light waves being in phase is known as _____.
60.     A single-frequency intense light source is known as a(n) _____.
61.     The reflective surfaces on a laser diode structure form a(n) _____ that produces in-phase light waves.
62.     For normal operation, LED and ILDs are _____ (reverse, forward)-biased.
63.     Which is faster, an LED or ILD?
64.     Which produces the brightest light, an LED or ILD?
65.     During normal operation, all photodiodes are _____ (reverse, forward)-biased.
66.     Light falling on the PN junction of a photodiode causes the diode's _____ current to increase.
67.     The most sensitive and fastest light detector is the _____.
68.     68-.The two main circuits in a fiber-optic receiver are _____.
69.     The product of the bit rate and distance of a system is 90 Mbits·km/s. The rating at 3 km is _____ Mbits/s.
In today's systems, the average maximum distance between repeaters is between _____ and _____ mi.
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