IECEP COMPILATION ESAT 1. Television stations are often operated in geographically separate areas and there are areas of the country where, because of population density, not all television channels are utilized. This unused spectrum between TV stations are called
8. He developed the oldest type of fuel cells which is the Alkaline Fuel Cells Ans. Francis Bacon 9. There are few major tidal energy generating power plants in operation. The main one is the __________________ in Northern France built in 1966 and has a capacity of 240 MW.
Ans. White Spaces
Ans. Ge Rance River
2. A radio that includes a transmitter in which the operating parameters of frequency range, modulation type or maximum output power, can be altered by making a change in software w/o making any changes to hardware components.
10. It is a diagnostic application or device that a network administrator can purchase and install on a network workstations or attach to the network media to monitor and capture data packets for subsequent analysis.. Ans. Sniffer
Ans. Software Defined Radio 3. It is an intelligent wireless communication system that is aware of its surrounding environment, and uses the methodology of understanding-by-building to learn from the environment and adapt its internal states to statistical variations in the incoming RF stimuli by making corresponding changes in certain operating parameters in real-time.
11. _______________ is a secret key encryption technology that is used in client/server environments for secure authentication between computers. Ans. Kerberos 12. What is the circuit which has a purpose p urpose to quiet a receiver in the absence of a received signal?
Ans. Cognitive Radio
Ans. Squelch circuit
4. Control signals sent in a voice channel at voice frequencies.
13. What is network node dedicated to interfacing between the network and one or more printers?
Ans. in-band signals Ans. Print server 5. It is a channel model mod el in which the input and output alphabets x and y are discrete sets and the channel is memoryless
14. Signal sent by the network to the calling telephone to indicate that the called party is being alerted.
Ans. The Discrete Memoryless Chanel Ans. Ringback signal “
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6. He is The Prophet of the Integrated Circuit . 15. Abrupt variations in timing of a digital signal Ans. Geoffrey Dummer Ans. Jitter 7. _____________________ is a harmful group of bacteria which can live inside cooling towers as well as in hot water systems, warm freshwater ponds, and creeks
16. The deviation of a wave as it passes an obstacle or passes through a small aperture Ans. Diffraction
Ans. Legionella 17. The speed of transmission of a signal along a waveguide.
Ans. Group velocity 18. A distance far enough from an antenna that local inductive and capacitive effects are insignificant. Ans. Far-field region 19. The lobe in the direction of maximum radiation. Ans. Main lobe 20. A waveguide device that has low loss in one direction and high loss in the other. o ther. Ans. Isolator 21. In a klystron, a cavity that velocity-modulates the electron beam is ____.
27. Generally used only on VHF and UHF bands because their length becomes prohibitive at the lower frequencies. Ans. Collinear antenna 28. A basic antenna connected to a transmission line plus one or more additional conductors that are not connected to the transmission line form a Ans. Parasitic array 29. The ability of an antenna to send or receive signals over a narrow horizontal directional range is referred to as Ans. Directivity
22. A balanced modulator eliminates which of the following from its output?
30. It is a phenomenon caused by any support insulators used at the ends of the wire antenna and has the effect of adding a capacitance to the end of each wire.
Ans. Carrier
Ans. End effect
23. A one-quarter wavelength of coaxial or balanced transmission line of a specific impedance connected between a load and a source in order to match impedances is
31. A type of antenna array where the maximum radiation is along the main axis of the antenna.
Ans. Q Ans. Q section
32. What antenna is often used vertically as either a mobile or base antenna in VHF and UHF systems?
Ans. Buncher
24. When the characteristic impedance of the transmission line matches the output impedance of the transmitter and the impedance of the antenna itself,
Ans. End-fire array
Ans. 5/8 λ antenna antenna
Ans. Maximum power transfer will take place
33. To obtain selectivity while eliminating the image problem, it is best to use a
25. A stacked collinear antenna consisting of halfwave dipoles spaced from one another by one-half wavelengths is the
Ans. Dual-conversion Receiver
26. It is a variable inductor, one or more variable capacitors, or a combination of these components connected in various configurations.
34. It uses switching techniques but with a scheme of pulse-width modulation and are found primarily in audio applications but have also been used in low and medium frequency RF amplifiers such as those used in AM broadcast transmitters
Ans. Antenna Ans. Antenna tuners
Ans. Class S Amplifiers
Ans. Broadside array
35. It uses a capacitive voltage divider instead of a tapped inductor to provide feedback. Ans. Colpitts Oscillator
Ans. Channel service unit 45. Is one in which all computers share their resources with all the other computers on the network.
36. It refers to any noise that has equal power per octave rather than per hertz.
Ans. Peer-to-peer client/server network
Ans. Pink noise
Ans. 51.84 Mbps
37. It provides the desired frequency response but have a constant time delay in the passband.
47. Is a device which operates op erates in the Network layer and it makes forwarding decisions on the basis of network addresses.
46. OC-1 (STS-1) line rate is
Ans. Bessel Ans. Router 38. It is the rate of change of amplitude with frequency in a filter.
48. Is a multiport bridge that provides bridging function.
Ans. Roll off Ans. Switch 39. Passes all frequencies equally well over its design range but has a fixed or predictable phase shift characteristics. characteristics.
49. IP version 4 address length is Ans. 32 bits
Ans. All-pass Ans. All-pass filter 40. The tendency of electrons flowing in a conductor to flow near and or the outer surface of the conductor frequencies in the VHF, UHF and microwave regions.
50. Is an access method used primarily with LANs configured in a bus topology. Ans. CSMA/CD 51. Is an n-bit data register inside the UART that keeps track of the UART s transmit and receive buffer registers.
Ans. Skin effect
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41. Is an error-correcting code used for correcting transmission errors in synchronous data streams.
Ans. Status Word register
42. Is an empirical record of a system s actual bit error performance
52. Is a redundancy error detection scheme that uses parity to determine if a transmission error has occurred within a message and is sometimes called message parity.
Ans. BER
Ans. Longitudinal redundancy check
43. Modulation which combines encoding and modulation to reduce the probability of error.
53. Is a PCM system s ystem which uses a single bit PCM code to achieve digital transmission of analog signals.
Ans. TCM
Ans. Delta modulation
44. Is used to interface DTEs to digital transmission channels
54. Is the ratio of the largest possible magnitude to the smallest possible
Ans. Hamming code ’
magnitude that can be decoded by the digital-toanalog converter. Ans. Dynamic range 55. Is an OSI Layer which is responsible for providing error-free communications across the physical link co nnecting primary and secondary stations (nodes)
characters, numbers, and special characters is called? Ans. Morse code 64. The process restoring a noise-corrupted signal to its original value is called? Ans. Regeneration Ans. Regeneration 65. A transmission line that is terminated with its characteristic characteristic impedance is called?
Ans. Data Link layer Ans. Flat line 56. A/an _______ is a range of frequency in which the upper frequency is double the lower frequency.
66. This indicates how many divisions the analog-todigital conversion process uses.
Ans. Octave
Ans. Resolution Ans. Resolution
57. In PCM system, it is the ratio of the maximum input voltage level to the smallest voltage level that can be quantized
67. The process of rounding-off the values of the flat top samples to a certain predetermined levels in order to make a finite number of levels is called?
Ans. Dynamic range 58. It is an undesired shift or width change in digital bits of data due to circuitry action which causes bits to arrive at different times Ans. Jitter
68. The feedback decoder simplifies to a form called __. Ans. Majority Logic Decoder
59. It is a connecting device between two internetworks that use different models
69. If g(t)=0 for t>T, the signal is called __. Ans. Full-Response CPM
Ans. Gateway ’
60. An error detection method which uses one s complement arithmetic Ans. Checksum 61. It is used in wireless applications in which stations must be able to share the medium without interception by an eavesdropper and without being subject to jamming from a malicious intruder Ans. Spread spectrum 62. The minimum sampling rate according to Nyquist Theorem Ans. Twice the highest frequency of a signal 63. A code that consists of dots and dashes in particular sequence to represent
Ans. Quantization
70. ASK, PSK and PAM are sometimes called __. Ans. Linear Modulation Schemes 71. A bandpass digital Pulse Amplitude Modulation(PAM) is also called __. Ans. ASK Ans. ASK 72. A Signal components arriving via different propagation paths may add destructively, resulting in a phenomenon called __. Ans. Signal Fading 73. A frequently occurring problem with electromagnetic wave propagation via sky wave in the high frequency (HF) range is __.
Ans. Signal Multipath
Ans. Forward Acting Error Correction
74. The amount of redundancy introduced by encoding the data is measured by the ratio n/k . The reciprocal of this ratio, namely k/n is called __.
82. Is a noise like high frequency signal, binary in nature. Thus it looks like pulses
Ans. Code Rate 75. Non-trivial Encoding involves taking k information bits at a time and mapping each k-bit sequence into a unique n-bit sequence. Ans. Code word 76. This filter is used to recover original signal from its sampled version. Ans. Interpolation Filter 77. The first security mechanism for WiFi, which is based on the RC4 encryption algorithm Ans. Wireless Encryption Protocol 78. A protocol designed for highly accurate clock synchronization focused especially on test and measurement, as well as power engineering. Ans. Precision Time Protocol 79. It is a parallel three-conductor line consisting of a thin centre strip and two thin ground strips on a dielectric substrate. Ans. Coplanar Lines 80. The total complex power impressed by a current source within a region is equal to the sum of the time-average power dissipated as heat inside the region, the complex power transmitted from the region and 2wj times the difference between time-average magnetic and electric energies stored within the region. This is stated in ___. Ans. Poynting theorem 81. It is an error control method when errors are detected and corrected by proper coding techniques at the receiver.
Ans. Pseudo-Noise 83. To utilize the available bandwidth efficiency and to increase the number of users, what is commonly employed? Ans. Frequency Reuse 84. Energy efficiency is reached by turning hardware parts off or to a sleep mode with minimal energy consumption as often as possible. This principle is commonly known as? Ans. Duty-Cycling 85. The following energy sources can be us ed for energy harvesting except for? Ans. Human Body 86. A type of microphone that pick-ups from the front and back equally well with little or no pickup from the sides. Ans. Bidirectional microphone 87. It involves the interplay of light with the atmosphere and the physical origin of the observed optical phenomena. Ans. Meteorological Optics 88. These cables are composed of several fibers together inside a small plastic tube, which are, in turn, wound around a central strength member and jacketed, providing a small, high fiber count cables. Ans. Loose tube cables 89. The tool that clamps the connector to the cable permanently. Most of it have hexagonal crimps sized for each connector type and replaceable jaws for different connectors. Ans. Crimpers
90. It is the amount of signal that is picked up by a quiet conductor (a conductor with no signal being transmitted over it at the moment) from other conductors that are conducting data. Ans. Crosstalk 91. In optical wireless communication, the transmitted data are modulated onto a light beam, usually in a form of a laser, it is commonly termed as ___________.
99. Type of coding that use flash encoders which are more complex but are more suitable for high-speed applications Ans. Word-at-a-time 100. Type of coding that determines each digit of the PCM code sequentially and produce a compromise between speed or complexity Ans. Digit-at-a-time 101. Type of coding that compares PAM signal to a ramp waveform while a binary counter is being advanced to a uniform rate
Ans. Free Space Optics 92. BFWA stands for?
Ans. Level-at-a-time Ans. Broadband Fixed Wireless Access 93. It is mainly dealing with use us e of the radio spectrum, and prevention of HAP (High Altitude Platforms) and corresponding ground equipment from causing harmful interference to other use types sharing the same frequency band. Ans. Radio Regulation 94. Process of converting an infinite number of facilities to a finite number of conditions
102. A distortion that occurs when DAC do not follow exactly the fast rate of analog input Ans. Slope overload 103. It limits the frequency of the analog input signal to standard voice band Frequency Ans. Bandpass filter
Ans. Quantization
104. Sampling technique where the tops of the analog waveform retain their natural shape
95. The storage time of the capacitor during which the ADC converts the sampling voltage to a PCM code
Ans. Natural sampling
96. The time that Q1 (FET) is ON and the capacitor charges (or discharges)
105. Its purpose is to encode the minimum amount of speech information necessary to reproduce a perceptible message with fewer bits than those needed by conventional encoder/decoder
Ans. Aperture Ans. Aperture time
Ans. Vocoder
97. It is the most common method of sampling in PCM systems
106. Common mode rejection ratios that are common in balanced transmission lines
Ans. Flat-top sampling
Ans. 40 dB to 70 dB
98. It is also called as Pulse Duration Modulation and Pulse Length Modulation
107. The cancellation of common mode signals
Ans. Conversion time “
Ans. PWM
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Ans. Common mode rejection 108. Is simply a flat conductor sandwiched between two ground planes
Ans. Stripline 109. Is simply a flat conductor separated from a ground plane by an insulating ins ulating dielectric material Ans. Microstrip
118. It is the name given to the area between the ceiling and the roof in a single-story building or between the ceiling and the floor of the next higher level in a multistory building. Ans. Plenum
110. A technique that can be used to locate an impairment in a metallic cable
119. It is comprised of four pairs of 24 AWG copper wire encapsulated in a common metallic foil shield with a PVC outer sheath
Ans. Time domain reflectometry
Ans. Foil twisted pair
111. Is simply a piece of additional transmission line that is placed across the primary line as close to the load as possible
120. Two local area networks that the CAT-3 UTP cable was designed to accommodate its requirements
Ans. Transmission line stub
Ans. IEEE 802.5 Token Ring (16 Mbps) and IEEE 802.3 10Base-T Ethernet (10Mbps)
112. Are used to match transmission lines to purely resistive loads whose resistance is not equal to the characteristic impedance of the line Ans. Quarter-wavelength transformers
121. Is an error-correcting code used for correcting c orrecting transmission errors in synchronous data streams.
113. Is a luminous discharge that occurs between the two conductors of a transmission line when the difference of potential between them exceeds the breakdown voltage of the dielectric insulator
122. Is a handshake from a DCE in response to an active condition on RTS from a DTE.
Ans. Corona
Ans. CTS
114. A difference of potential between two conductors of a metallic transmission line
123. Are used with transport layer protocols to identify processes running on computers.
Ans. Hamming code
Ans. Dielectric heating losses Ans. Port number 115. The ratio of the ac resistance to the dc resistance of a conductor Ans. Resistance ratio 116. It is used to express the attenuation (signal loss) and the phase shift per unit length of a transmission line. Ans. Propagation constant, Propagation coefficient 117. A coaxial cable with one layer of foil insulation and one layer of braided shielding Ans. Dual shielded
124. Is a reliable connection oriented protocol which operates at the OSI transport layer Ans. TCP 125. Is an unreliable connectionless protocol that operates at the Transport layer of the OSI seven layer hierarchy. Ans. UDP 126. Is a connectionless protocol which provides best effort delivery, and is an OSI Layer 3 protocol. Ans. Internet Protocol
127. The electrical specifications for RS 449 are Ans. RS-422 and RS-423 128. A start bit is always a Ans. Logic 0 129. Is sometimes called start / stop transmission Ans. Asynchronous Ans. Asynchronous data transmission transmission 130. TCP/IP stands for Ans. Transmission control protocol / Internet Protocol 131. With QPSK, the number of input bits is equal to Ans. 2 132. Is a form of o f digital modulation wherein the digital information is contained in both the amplitude and the phase of the transmitted carrier. Ans. QAM 133. Is an eight-bit fixed- length character set developed by IBM Ans. EBCDIC 134. E1 transmission bit rate is Ans. 2.048 Mbps
IBM for use in System Network Architecture (SNA) environments. Ans. Synchronous Data Link Control 139. The nominal maximum length of the RS232 interface is Approximately Ans. 50 feet 140. Official name is Interface Between Data Terminal Equipment And Data Communications Equipment Employing Serial Binary Data Interchange Ans. RS232 141. Is an OSI layer which controls and ensures the end-to-end integrity of data message propagated through the network between two devices. Ans. Transport Layer 142. In ISDN, the 2B 2 B + D service is called Ans. Basic rate interface 143. ATM has a fixed length data packet whose length is Ans. 53 bytes 144. The default mask for a class B network is Ans. 255.255.0.0
135. Is a multiplexing system similar to conventional time-division multiplexing except that it was developed to be used with optical fibers.
145. Direct broadcasts are data packets where the host portion of the destination IP address contains
Ans. SONET
Ans. All Ans. All binary 1s
136. Is a special purpose router that allows LANs to access the Internet.
146. It is a class of IP addresses used for multicasting. Ans. Class D
Ans. Gateway 137. Is a medium access control which is used for wireless LANs
147. For class C IP addresses, the netid bits is composed of Ans. 24 bits
Ans. CSMA/CA 138. Is a synchronous bit-oriented protocol developed in the 1970s by
148. For class A IP addresses, the netid bits is composed of
Ans. 8 bits 149. The maximum segment length for Ethernet 100 Base-T cable is
157. Is the highest frequency that can be propagated directly upward and still be returned to Earth by the ionosphere. Ans. Critical frequency
Ans. 100 meters 158. As the distance from a point source antenna doubles, the power density decreases by a factor of
150. It is an intelligent two port connectivity device used on LANs to direct data frames between two LAN segments based on hardware (MAC) addresses that are burned into the NICs of every device connected to the network.
Ans. 4
Ans. Bridge
Ans. 377 ohms
151. The bit sequence for a flag in SDLC is
160. It is any frequency other than the selected radio frequency carrier that, if allowed to enter a receiver and mix with the local oscillator, will produce a cross product frequency that is equal to the intermediate frequency.
Ans. 01111110 (7E hex) hex) 152. It is a synchronous character oriented data-link protocol developed by IBM Ans. Bisync 153. With this flow control, a source station can transmit several frames in succession before receiving an acknowledgment .There is only one acknowledgment for several transmitted frames. Ans. Sliding window 154. With this encoding technique, there are two nonzero voltage levels, but both polarities represent logic 1s, and 0 volt represents logic 0. Logic 1s are inverted in polarity from the previous logic 1. Ans. BPRZ AMI 155. It is an OSI layer which provides details that enable data to be routed between devices in an environment using multiple networks, subnetworks, or both. Ans. Network Layer 156. It is an OSI layer which provides independence to the application processes by addressing any code or syntax conversion necessary to present the data to the network in a common communications format. Ans. Presentation Layer
159. It is the characteristic impedance of free space
Ans. Image frequency 161. It is the band of frequencies centered around the VCO natural frequency where a PLL can initially establish or acquire frequency lock with an external input signal Ans. Capture Range 162. It is the minimum RF signal level that can be detected at the input to the receiver and still produce a usable demodulated information signal. Ans. Sensitivity, Receiver Threshold 163. It occurs when oscillating mechanical stresses applied across a crystal lattice structure generate electrical oscillations and vice versa. Ans. Piezoelectric Effect 164. A quarter wavelength transmission line terminated in an open circuit is equivalent to a Ans. Series LC circuit 165. A quarter wavelength transmission line terminated in a short circuit is equivalent to A Ans. Parallel LC circuit
166. It is a circuit device used to connect a balanced transmission line to an unbalanced load. Ans. Balun 167. Which of the following reliability specifications is referred to as General Specification for Reliability of Production of Electronic Equipment ? “
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Ans. MIL-R-19610 168. A third or safety wire which is carried throughout the residence along with the phase and neutral wires that carry the desired 60 Hz power is referred to as the _______ Ans. Green wire 169. Which of following material does not tend to readily attract or give up electrons when brought in contact or rubbed with other materials (neutral on the triboelectric scale): Ans. Cotton 170. Current fiber optic communication systems operate in the given nominal wavelength regions EXCEPT for one: A. 820 nm
B. 1440 nm
C. 1330 nm
D. 1550 nm
