MCQOPTIONS
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MCQOPTIONS
This section includes 210 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics and Telecommunication Engineering [ENT knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
Formats of signal units in CCTTT no. 7 signalling system are ________________ |
| A. | message signalling unit |
| B. | link-status signalling unit |
| C. | fill-in unit |
| D. | all of the above |
| Answer» E. | |
| 52. |
On an average, one call arrives every 5 seconds. During a period of 10 seconds, what is the probability that no call arrives? |
| A. | 0.123 |
| B. | 0.135 |
| C. | 0.595 |
| D. | 0.455 |
| Answer» C. 0.595 | |
| 53. |
Standards of CCITT Signalling system are _____ |
| A. | ss6 |
| B. | ss5 |
| C. | ss7 |
| D. | both 1 and 3 |
| Answer» E. | |
| 54. |
Major classes of signalling are ___________ |
| A. | customer line signalling |
| B. | in channel signalling |
| C. | common channel signalling |
| D. | both 2 and 3 |
| Answer» E. | |
| 55. |
What are the types of inter register signalling? |
| A. | en-bloc signalling |
| B. | overlap signalling |
| C. | both 1 and 2 |
| D. | none of the above |
| Answer» D. none of the above | |
| 56. |
In Erlang's analysis of efficient telephone line usage he derived the formulae for two important cases, ________, |
| A. | erlang-b |
| B. | erlang-c |
| C. | erlang-a |
| D. | both 1 and 2 |
| Answer» E. | |
| 57. |
Inter register signalling can be done by _________ |
| A. | link by link basis |
| B. | end to end basis |
| C. | line signalling |
| D. | all of the above |
| Answer» E. | |
| 58. |
Erlang determined GoS of lost call system of finite number of trunks based on assumptions: 1. Pure chance traffic 2. Statistical equilibrium 3. Full availability 4. calls which face congestion and get lost |
| A. | 1 and 2 |
| B. | 2 and 3 |
| C. | 3 and 4 |
| D. | all of the above |
| Answer» E. | |
| 59. |
Traffic tables show relationships of ____________ |
| A. | offered traffic \a\ |
| B. | blocking probability (gos) |
| C. | number of trunks \n\ |
| D. | all of the above |
| Answer» E. | |
| 60. |
A group of 10 servers carry a traffic of 5E. If the average duration of calls is 1.5 minutes, calculate the number of calls put through by a single server and a group as a whole in 1 hr period. |
| A. | 20 calls and 200 calls |
| B. | 10 calls and 200 calls |
| C. | 5 calls and 100 calls |
| D. | none of the above |
| Answer» B. 10 calls and 200 calls | |
| 61. |
A group of 5 trunks carry a traffic of 2E. Find 1. GoS 2. Probability that only one trunk is busy. |
| A. | 0.037 and 0.275 |
| B. | 0.027 and 0.325 |
| C. | 0.047 and 0.475 |
| D. | none of the above |
| Answer» B. 0.027 and 0.325 | |
| 62. |
Over 10 minutes observation interval, 20 subscribers initiate a call. Total duration of calls is 2400sec. Calculate load offered to network by the subscribers and average subscriber traffic? |
| A. | 4e and 0.1e respectively |
| B. | 2e and 0.5e respectively |
| C. | 3e and 1.5e respectively |
| D. | 1e and 0.2e respectively |
| Answer» B. 2e and 0.5e respectively | |
| 63. |
If more number of cells are necessary in the frequency reuse distance, then the segmentation & dualization techniques get ________ |
| A. | United |
| B. | Divided |
| C. | Â Restricted |
| D. | Filtered |
| Answer» B. Divided | |
| 64. |
Which method of cellular network assists in minimizing the co-channel interference associated with the angle of degree? |
| A. | Cell Splitting |
| B. | Cell Sectoring |
| C. | Cell Segmentation & Dualization |
| D. | None of the above |
| Answer» C. Cell Segmentation & Dualization | |
| 65. |
Which among the following represents the flawless hand-off with no perceivable interruption of service? |
| A. | Hard hand-off |
| B. | Soft hand-off |
| C. | Â Intracell hand-off |
| D. | Intercell hand-off |
| Answer» C. Â Intracell hand-off | |
| 66. |
Which effect is widespread in adjacent-channel interference especially after the reception of a weak signal by a mobile user from the base-station? |
| A. | Near-far effect |
| B. | Doppler\s effect |
| C. | Capture effect |
| D. | Kendall effect |
| Answer» B. Doppler\s effect | |
| 67. |
Which antennas are used at the center of the cells for the system with hexagonal-shaped cells? |
| A. | Omni-directional antennas |
| B. | Sectored directional antennas |
| C. | Both a and b |
| D. | Â None of the above |
| Answer» B. Sectored directional antennas | |
| 68. |
The propagation model that estimates radio coverage of a transmitter is called ___________ |
| A. | Large scale propagation model |
| B. | Small scale propagation model |
| C. | Fading model |
| D. | Okumura model |
| Answer» B. Small scale propagation model | |
| 69. |
The mechanism behind electromagnetic wave propagation cannot be attributed to _____ |
| A. | Reflection |
| B. | Diffraction |
| C. | Scattering |
| D. | Sectoring |
| Answer» E. | |
| 70. |
The most comman dial up service used by a person making home telephone call is_____________ |
| A. | Analog Switched Service |
| B. | Analog Leased Service |
| C. | Switched/56 Service |
| D. | Digital Data Service |
| Answer» B. Analog Leased Service | |
| 71. |
Small scale propagation model is also known as _______ |
| A. | Fading model |
| B. | Micro scale propagation model |
| C. | Okumura model |
| D. | Hata model |
| Answer» B. Micro scale propagation model | |
| 72. |
For Telephone voice Transmission to use a T line, the signal must be __________________ before the multiplexed. |
| A. | Synchronized |
| B. | Modulated |
| C. | Sampled |
| D. | Filterd |
| Answer» D. Filterd | |
| 73. |
Which of the following techniques do not help in expanding the capacity of cellular system? |
| A. | Sectoring |
| B. | Scattering |
| C. | Splitting |
| D. | Microcell zone concept |
| Answer» C. Splitting | |
| 74. |
Cell splitting increases the capacity of a cellular system since it increases the number of times ________ are reused. |
| A. | Cells |
| B. | Channels |
| C. | Transmitters |
| D. | Mobile stations |
| Answer» C. Transmitters | |
| 75. |
Which of the following technology distributes the coverage of the cell and extends the cell boundary to hard-to-reach places? |
| A. | Cell splitting |
| B. | Scattering |
| C. | Sectoring |
| D. | Micro cell zone concept |
| Answer» E. | |
| 76. |
Small scale variations of a mobile radio signal are directly related to _______ |
| A. | Impulse response of mobile radio channel |
| B. | Impulse response of base station |
| C. | Frequency response of antenna |
| D. | Frequency response of base station |
| Answer» B. Impulse response of base station | |
| 77. |
Discretization of multipath delay axis of impulse response into equal time delay segments is called __________ |
| A. | Excess delay bins |
| B. | Delay bins |
| C. | Discrete bins |
| D. | Digital bins |
| Answer» B. Delay bins | |
| 78. |
In cellular telephone network, which component controls the switching between public wireline telephone network and the base station of cells for supporting the different calls between landline to mobile, mobile to landline and mobile to mobile calls? |
| A. | Electronic Switching Center (ESC) |
| B. | A Cell Controller |
| C. | Radio Transmitter & Receiver |
| D. | A common communication protocol |
| Answer» B. A Cell Controller | |
| 79. |
In a cellular telephone system, which type of interference results from imperfect design of filters in receivers by allowing nearby frequencies to enter the receiver? |
| A. | Co-channel Interference |
| B. | Adjacent-channel Interference |
| C. | Both a and b |
| D. | None of the above |
| Answer» C. Both a and b | |
| 80. |
If the system is designed with the usage of hexagonal-shaped cells, how are the base-stations located? |
| A. | At the centre of cell |
| B. | At the edge of cell |
| C. | At the corner of the cell |
| D. | All of the above |
| Answer» E. | |
| 81. |
Station Busy is sometime called |
| A. | Fast Busy |
| B. | Slow Busy |
| C. | Short Busy |
| D. | Long Busy |
| Answer» C. Short Busy | |
| 82. |
Relation between gain and effective aperture is given by ______ |
| A. | G=(4πAe)/λ2 |
| B. | G=(4π λ2)/ Ae |
| C. | G=4Ï€Ae |
| D. | G=Ae/λ2 |
| Answer» B. G=(4Ï€ λ2)/ Ae | |
| 83. |
Which of the following is not a channel parameter? |
| A. | Bandwidth |
| B. | Coherence time |
| C. | Rms delay spread |
| D. | Doppler spread |
| Answer» B. Coherence time | |
| 84. |
Which of the following is not an advantage of micro cell zone technique? |
| A. | Reduced co channel interference |
| B. | Improved signal quality |
| C. | Increase in capacity |
| D. | Increasing number of base stations |
| Answer» E. | |
| 85. |
Flat fading channel is also known as _____ |
| A. | Amplitude varying channel |
| B. | Wideband channel |
| C. | Phase varying channel |
| D. | Frequency varying channel |
| Answer» B. Wideband channel | |
| 86. |
For fast fading channel, the coherence time of the channel is smaller than _______ of transmitted signal. |
| A. | Doppler spread |
| B. | Bandwidth |
| C. | Symbol period |
| D. | Coherence bandwidth |
| Answer» D. Coherence bandwidth | |
| 87. |
The time dispersive properties of wideband multipath channel are quantified by ______ and _______ |
| A. | Mean excess delay, rms delay spread |
| B. | Doppler spread, rms delay spread |
| C. | Doppler spread, coherence time |
| D. | Mean excess delay, Doppler spread |
| Answer» B. Doppler spread, rms delay spread | |
| 88. |
The received power of a wideband signal fluctuates significantly when a receiver is moved about a local area. State whether True or False. |
| A. | True |
| B. | false |
| C. | Both A and B |
| D. | Cant Say |
| Answer» C. Both A and B | |
| 89. |
Why is the phase of individual multipath components are not received in RF Pulse system? |
| A. | Due to use of duplexer |
| B. | Due to use of ADC |
| C. | Due to use of flip flops |
| D. | Due to use of envelope detector |
| Answer» E. | |
| 90. |
Anyone who uses atelephone or data modem on the telephone circuit is a part of globle communication network called as__________________ and the pair of wires connecting a subscriber to the closest telephone office is called as ____________________. |
| A. | Personal Mobile Telephone Network,Twisted Pair |
| B. | World Wide Web, Subscriber Line |
| C. | Internet, Drop Line |
| D. | Public Telephone Network, Local Loop |
| Answer» E. | |
| 91. |
Free space propagation model is to predict ______,Which of the following do not undergo free space propagation? |
| A. | Received signal strength,Wired telephone systems |
| B. | Transmitted power, Satellite communication system |
| C. | Gain of transmitter,Microwave line of sight radio links |
| D. | Gain of receiver, Wireless line of sight radio links |
| Answer» B. Transmitted power, Satellite communication system | |
| 92. |
The free space model predicts that received signal decays as a function of _____ |
| A. | Gain of transmitter antenna |
| B. | T-R separation |
| C. | Power of transmitter antenna |
| D. | Effective aperture of the antenna |
| Answer» C. Power of transmitter antenna | |
| 93. |
Free space propagation model is to predict ______ and Propagation model that characterize rapid fluctuation is called ________ |
| A. | Transmitted power,Hata model |
| B. | Received signal strength, Fading model |
| C. | Gain of transmitter, Large scale propagation model |
| D. | Gain of receiver,Okumura model |
| Answer» C. Gain of transmitter, Large scale propagation model | |
| 94. |
Differentiate GSM and DECT. |
| A. | Both B and C |
| B. | GSM -Range is up to 70km. DECT-Range is limited to about 300m. |
| C. | GSM- Global systems for mobile communications DECT- Digital enhanced cordless elecommunications |
| D. | None of the above |
| Answer» B. GSM -Range is up to 70km. DECT-Range is limited to about 300m. | |
| 95. |
Which hand-off stage deals with the relinquishment of unnecessary frequency channels by keeping the availability for other mobile users? |
| A. | Â Initialization |
| B. | Resource Reservation |
| C. | Call Execution |
| D. | Call Completion |
| Answer» E. | |
| 96. |
What is the order of typical values of rms delay spread in outdoor mobile radio channels? |
| A. | Microseconds |
| B. | Nanoseconds |
| C. | Seconds |
| D. | Minutes |
| Answer» B. Nanoseconds | |
| 97. |
______ leads to time dispersion and frequency selective fading. What is characteristic of flat fading? |
| A. | Doppler spread, Mobile radio channel has constant gain |
| B. | Multipath delay spread, Non linear phase response |
| C. | Time dispersive parameters, Linear phase response |
| D. | Frequency delay spread,Bandwidth is greater than the bandwidth of transmitted signal |
| Answer» C. Time dispersive parameters, Linear phase response | |
| 98. |
Power delay profile and magnitude frequency response of a mobile radio channel are related through _______ |
| A. | Laplace Transform |
| B. | Fourier Transform |
| C. | S Transform |
| D. | Wavelet Transform |
| Answer» C. S Transform | |
| 99. |
_____ and coherence bandwidth are inversely proportional to one another.Coherence bandwidth is a statistical measure of range of frequencies over which channel is considered _______ |
| A. | Rms delay spread, Flat |
| B. | Mean excess delay,Frequency selective |
| C. | Excess delay spread,Time variant |
| D. | Doppler spread, Time dispersive |
| Answer» B. Mean excess delay,Frequency selective | |
| 100. |
Verify True or False A.Frequency domain channel sounding technique do not require hard wired synchronization between transmitter and receiver. B.There is no relationship between time domain and frequency domain techniques. |
| A. | Both Statements True |
| B. | Both Statements False |
| C. | Only A true |
| D. | Only B true |
| Answer» E. | |