1. Which frequency range is used for TV transmission?
(A) 30 HZ – 300 Hz
(B) 30 kHZ – 300 kHZ
(C) 30 MHz – 300 MHz
(D) 30 GHz – 300 GHz
Multiple Choice
ID- 16174
BSEB, 2009, 2018 (C)
2. Sky wave communication is based upon:
(A) reflection by ionosphere
(B) absorption by ionosphere
(C) transmission through ionosphere
(D) none of these
Multiple Choice
ID- 16175
3. The loss of strength of a signal while propagating through a medium is known as:
(A) reception
(B) absorption
(C) transmission
(D) attenuation
Multiple Choice
ID- 16176
4. A basic communication system consists of: (1) transmitter (2) information source (3) receive (4) channel (5) receiver Choose correct sequence in which these are arranged in a basic communication system:
(A) 12345
(B) 21453
(C) 24135
(D) 25143
Multiple Choice
ID- 16177
5. The process of increasing the strength of a signal using an electronic circuit is called:
(A) amplification
(B) modulation
(C) demodulation
(D) transmission
Multiple Choice
ID- 16178
6. Modem is a device which performs:
(A) modulation
(B) demodulation
(C) rectification
(D) modulation and demodulation
Multiple Choice
ID- 16179
7. The mode of propagation used by short wave broadcast services is:
(A) space wave
(B) sky wave
(C) ground wave
(D) both 'A' and 'C'
Multiple Choice
ID- 16180
8. Large bandwidth for higher data rate is archieved by using:
(A) high frequency carrier wave
(B) hight frequency audio wave
(C) low frequency carrier wave
(D) low frequency audio wave
Multiple Choice
ID- 16181
9. A male voice after modulation-transmission sounds like that of a female to the receiver. The problem is due to:
(A) poor selection of modulation index (selected 0 < μ < 1)
(B) poor bandwidth selection of amplifiers
(C) poor selection of carrier frequency
(D) loss of energy in transmission
Multiple Choice
ID- 16182
10. Which of the following frequency/frequencies will be suitable for beyond the horizon communication using sky waves?
(A) 10 kHz
(B) 10 MHz
(C) 1 GHz
(D) 1000 GHz
Multiple Choice
ID- 16183
11. Frequencies in the UHF range normally propagate by means of:
(A) ground waves
(B) sky waves
(C) surface waves
(D) space waves
Multiple Choice
ID- 16184
12. Which among the following is not a basic terminology used in electronic communication systems?
(A) Transducer
(B) Transmitter
(C) Telegraph
(D) Alltenuation
Multiple Choice
ID- 16185
13. Who invented world wide web?
(A) J.C.R. Licklider
(B) Tim Berners-Lee
(C) Alexander Graham Bell
(D) Samuel F.B. Morse
Multiple Choice
ID- 16186
14. If the whole earth is to be connected by line of sight communication using space waves (no restriction of antenna size or tower height) what is the minimum number of antennas required?
(A) 2
(B) 3
(C) 4
(D) 6
Multiple Choice
ID- 16187
15. The device which is a combination of a receiver and a transmitter is:
(A) Amplifier
(B) Repeater
(C) Transducer
(D) Modulator
Multiple Choice
ID- 16188
16. Which of the following is not a transducer?
(A) Loudspeaker
(B) Amplifier
(C) Microphone
(D) All of these
Multiple Choice
ID- 16189
17. The phenomenon of bending of electromagnetic wave, so that they are diverted towards the earth is similar to that of which phenomenon in optics?
(A) Reflection
(B) Polarisation
(C) Total internet reflection
(D) Dispersion
Multiple Choice
ID- 16190
18. Which of the following is an example of broadcast mode of communication?
(A) Radio
(B) Television
(C) Mobile
(D) Both A and B
Multiple Choice
ID- 16191
19. FM broadcast is preferred over AM broadcast because:
(A) it is less noisy
(B) reproduction is of much better quality
(C) it is more noisy
(D) both A and B
Multiple Choice
ID- 16192
20. Which of the following modes is used for line of sight communication as well as satellite communication?
(A) Ground wave
(B) Sky wave
(C) Space wave
(D) All of these
Multiple Choice
ID- 16193
21. Essential elements of a communication system are:
(A) transmitter and receiver
(B) receiver and communication channel
(C) transmitter and communication channel
(D) transmitter, communication channel and receiver
Multiple Choice
ID- 16194
22. The radio waves of frequency 30 MHz to 300 MHz belong to:
(A) high frequency band
(B) very high frequency band
(C) ultra high frequency band
(D) super high frequency band
Multiple Choice
ID- 16195
23. Through which mode of propagation, the radio waves can be sent from on place to another:
(A) ground wave propagation
(B) sky wave propagation
(C) space wave propagation
(D) all of them
Multiple Choice
ID- 16196
24. What should be the length of the dipole antenna for a carrier wave of frequency $3$ x $10^8$ Hz?
(A) 1 m
(B) 0.5 m
(C) 2 m
(D) 2.5 m
Multiple Choice
ID- 16197
25. The frequency band used in the downlink of satellite communication is:
(A) 9.5 to 2.5 GHz
(B) 896 to 901 MHz
(C) 3.7 to 4.2 GHz
(D) 840 to 935 MHz
Multiple Choice
ID- 16198
26. The waves that are bent down by the ionosphere are:
(A) ground waves
(B) surface waves
(C) space waves
(D) sky waves
Multiple Choice
ID- 16199
27. Which of the following devices is full duplex?
(A) Mobile phone
(B) Walky-talky
(C) Loud speaker
(D) Radio
Multiple Choice
ID- 16200
28. Audio signal cannot be transmitted because:
(A) the signal has more noise
(B) the signal cannot be amplified for distance communication
(C) the transmitting antenna length is very small to design
(D) the transmitting antenna length is very large and impracticable
Multiple Choice
ID- 16201
29. Who undertook the first space walk and in which year?
(A) Leonov, 1965
(B) Neil Armstrong, 1969
(C) Rakesh Sharma, 1998
(D) None of these
Multiple Choice
ID- 16202
30. The term used "to collect the information about an object and a place without physical contact" is called:
(A) modulation
(B) communication
(C) amplification
(D) remote sensing
Multiple Choice
ID- 16203
31. The velocity of electromagnetic wave is:
(A) $\ce{3 x 10^5 ms^{–1}}$
(B) $\ce{3 x 10^6 ms^{–1}}$
(C) $\ce{3 x 10^8 ms^{–1}}$
(D) $\ce{3 x 10^{10} ms^{–1}}$
Multiple Choice
ID- 16204
32. The audio frequencies range from:
(A) 20 Hz to 20,000 kHz
(B) 20 Hz to 20 kHz
(C) 20 kHz to 20,000 kHz
(D) None of these
Multiple Choice
ID- 16205
33. The wavelength of a wave of frequency 10 kHz is:
(A) 30 m
(B) 300 m
(C) 30 km
(D) 300 km
Multiple Choice
ID- 16206
34. The area served by an antenna of height 100 m is:
(A) $\ce{10^9 m^2}$
(B) $\ce{4 x 10^9 m^2}$
(C) $\ce{6 x 10^9 m^2}$
(D) $\ce{8 x 10^{10} m^2}$
Multiple Choice
ID- 16207
35. Which of the following is not transducer?
(A) Loudspeaker
(B) Amplifier
(C) Microphone
(D) Alll
Multiple Choice
ID- 16208
36. The space wave which are affected seriously by atmospheric conditions are:
(A) MF
(B) HUF
(C) VHF
(D) UHF
Multiple Choice
ID- 16209
37. An antenna is:
(A) Inductive
(B) Capacitive
(C) Resistive
(D) A transformer
Multiple Choice
ID- 16210
BSEB, 2018 (C)
38. From which layer of atmosphere are radio waves reflected?
(A) Ionosphere
(B) Mesosphere
(C) Chromosphere
(D) None of the above
Multiple Choice
ID- 16211
BSEB, 2019 (A)
39. The modulation index in amplitude modulation:
(A) is always zero
(B) lies between 0 and 1
(C) lies between 1 and ∞
(D) can never exceed 0.5
Multiple Choice
ID- 16212
40. The output of a digital computer is an example of:
(A) digital signal
(B) analog signal
(C) both (A) and (B)
(D) neither (A) nor (B)
Multiple Choice
ID- 16213
41. Name the man who was first to place his foot on the moon and in which year?
(A) Neil Armstrong, 1969
(B) James Van Allen, 1971
(C) Leonov, 1965
(D) None of these
Multiple Choice
ID- 16214
42. A microphone converts:
(A) sound signals into electric signals
(B) electrical signals into sound signals
(C) both (A) and (B)
(D) Neither (A) nor (B)
Multiple Choice
ID- 16215
43. A loudspeaker converts:
(A) electrical signals into sound signals
(B) sound signals into eletrical signals
(C) both (A) and (B)
(D) neither (A) nor (B)
Multiple Choice
ID- 16216
44. The sound produced by a tuning fork is a sort of:
(A) analog signal
(B) digital signal
(C) both (A) and (B)
(D) neither (A) nor (B)
Multiple Choice
ID- 16217
45. The length of a half wave dipole at 30 mega-hertz is:
(A) 5 m
(B) 10 m
(C) 25 m
(D) 80 m
Multiple Choice
ID- 16218
46. In space communication, the sound waves can be sent from one place to another:
(A) through space
(B) through wires
(C) by superimposing it on undamped electro-magnetic waves
(D) by superimposing it on damped electro-magnetic waves
Multiple Choice
ID- 16219
47. Which is more advantageous?
(A) analog data communication
(B) digital data communication
(C) both (A) and (B) are equally good
(D) depends on the situation
Multiple Choice
ID- 16220
48. Communication channel consists of:
(A) transmission line only
(B) optical fibre only
(C) free space only
(D) All of the above
Multiple Choice
ID- 16221
49. AM is used for broadcasting because:
(A) it is more noise immune than other modulation system
(B) it requires less transmitting power compare with other systems
(C) its use avoids receiver complexity
(D) No other modulation system can provide the necessary bandwidth faithful transmission
Multiple Choice
ID- 16222
50. Digital signals:
(A) represents values as discrete steps
(B) Do not represents values as discrete steps
(C) represent values steps
(D) represent random steps
Multiple Choice
ID- 16223
51. The Digital signals:
(A) deal with all sort of values
(B) can use decimal system
(C) can use binary system
(D) (B) and (C)
Multiple Choice
ID- 16224
52. Increase in frequency deviation results into:
(A) increase in noise of FM receiver
(B) decrease in noise of AM receiver
(C) increase in noise of Am receiver
(D) decrease in noise of FM receiver
Multiple Choice
ID- 16225
53. The number of codes obtained from an 8 bit combination is:
(A) 8
(B) 32
(C) 64
(D) 256
Multiple Choice
ID- 16226
54. The transmission media can be:
(A) guided only
(B) unguided only
(C) both (A) and (B)
(D) neither (A) nor (B)
Multiple Choice
ID- 16227
55. The device fitted in the satellite which receives signals from the earth station and transmits them in different directions its called:
(A) transmitter
(B) transponder
(C) amplifier
(D) transformer
Multiple Choice
ID- 16228
56. The height of a geostationary satellite above the surface of the earth is about:
(A) 100 km
(B) 3600 km
(C) 10000 km
(D) 36000 km
Multiple Choice
ID- 16229
57. Which of the following parameters is not used to define the orbit of a satellite?
(A) apogee
(B) perigee
(C) inclination
(D) modulation
Multiple Choice
ID- 16230
58. Basic componets of a transmitter are:
(A) message signal generator and antenna
(B) modulator and antenna
(C) signal generator and modulator
(D) message signal generator modulator and antenna
Multiple Choice
ID- 16231
59. Modulation is used to:
(A) reduce the band width used
(B) separate the transmission of different users
(C) ensure that intelligence may be transmitted long distance
(D) Allow the use of practical antenna
Multiple Choice
ID- 16232
60. A byte is a string of n bits. Then n equals:
(A) 8
(B) 6
(C) 4
(D) 2
Multiple Choice
ID- 16233
BSEB, 2021 (A)
61. Which of the following units is correct to measure attenuation?
(A) decibel
(B) ohm
(C) ampere
(D) volt
Multiple Choice
ID- 16234
62. The range of frequencies allotted for commercial FM radio broadcast is:
(A) 88 to 108 MHz
(B) 88 to 108 kHz
(C) 8 to 889 MHz
(D) None of these
Multiple Choice
ID- 16235
63. The range of frequencies allotted for commercial VHF TV broadcast is:
(A) 45 to 280 kHz
(B) 47 to 230 MHz
(C) 470 to 2300 kHz
(D) None of these
Multiple Choice
ID- 16236
64. The range of frequencies allotted for commercial UHF TV broadcast is:
(A) 470 to 980 kHz
(B) 47 to 960 MHz
(C) 470 to 960 MHz
(D) None of these
Multiple Choice
ID- 16237
65. The space waves which are affected seriously by atmospheric conditions correspond to:
(A) HF
(B) MF
(C) VHF
(D) UHF
Multiple Choice
ID- 16238
66. What is the wavelength of a TV station which transmits on 500 MHz?
(A) 0.3 m
(B) 0.6 m
(C) 0.6 km
(D) None
Multiple Choice
ID- 16239
67. The frequency range for high frequency band (HF) is:
(A) 3 Hz to 3 MHz
(B) 3 MHz to 30 MHz
(C) 30 MHz to 300 MHz
(D) None of these
Multiple Choice
ID- 16240
68. Basically, a communication system is a:
(A) transmitter
(B) receiver
(C) messenger
(D) None of these
Multiple Choice
ID- 16241
69. Present day communication systems are:
(A) electrical only
(B) electronic only
(C) optical only
(D) All of the above
Multiple Choice
ID- 16242
70. Major parts of a communication system are:
(A) transmitter and receiver
(B) receiver and communication channel
(C) transmitter and communication channel
(D) transmitter, receiver and communication channel
Multiple Choice
ID- 16243
71. The height of a TV transission tower at any place on the surface of the earth is 245m. The maximum distance up to which transmission of tower will reach is: