McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Bachelor of Science in Computer Science FY (BSc CS) , Bachelor of Computer Applications (BCA) , Bachelor of Science in Computer Science (BSc CS) .
| 51. |
The _____________speech is also called as reported speech |
| A. | direct |
| B. | indirect |
| C. | indefinite |
| D. | definite |
| Answer» B. indirect | |
| 52. |
A cordless telephone using separate frequencies for transmission in base and portable units is known as |
| A. | duplex arrangement |
| B. | half duplex arrangement |
| C. | either (a) or (b) |
| D. | neither (a) nor (b) |
| Answer» A. duplex arrangement | |
| 53. |
For attenuation of high frequencies we should use |
| A. | shunt capacitance |
| B. | series capacitance |
| C. | inductance |
| D. | resistance |
| Answer» A. shunt capacitance | |
| 54. |
A modem is classified as low speed if data rate handled is |
| A. | upto 100 bps |
| B. | upto 250 bps |
| C. | upto 400 bps |
| D. | upto 600 bps |
| Answer» D. upto 600 bps | |
| 55. |
VSB modulation is preferred in TV because |
| A. | it reduces the bandwidth requirement to half |
| B. | it avoids phase distortion at low frequencies |
| C. | it results in better reception |
| D. | none of the above |
| Answer» A. it reduces the bandwidth requirement to half | |
| 56. |
A woofer should be fed from the input through a |
| A. | low pass filter |
| B. | high pass filter |
| C. | band pass filter |
| D. | band stop filter |
| Answer» A. low pass filter | |
| 57. |
Which of the following is an indirect way of generating FM? |
| A. | armstrong modulator |
| B. | varactor diode modulator |
| C. | reactance fet modulator |
| D. | reactance bipolar transistor |
| Answer» A. armstrong modulator | |
| 58. |
When the length of antenna is a whole wavelength |
| A. | the radiation at right angles is zero |
| B. | the radiation at right angles is maximum |
| C. | the radiation is zero in all directions |
| D. | the radiation is maximum in all directions |
| Answer» A. the radiation at right angles is zero | |
| 59. |
Circular polarization |
| A. | is useful in reducing depolarization effect on received wave |
| B. | involves critical alignment of transmitting and receiving antenna |
| C. | is useful in discrimination between reception of adjacent beams |
| D. | none of the above |
| Answer» A. is useful in reducing depolarization effect on received wave | |
| 60. |
An FM radio receiver which is tuned to a 91.6 MHz broadcast station may receive an image frequency of __________ MHz. |
| A. | 102.3 |
| B. | 113 |
| C. | 70.2 |
| D. | 80.9 |
| Answer» B. 113 | |
| 61. |
For telegraphy the most commonly used modulation system is |
| A. | fsk |
| B. | two tone modulation |
| C. | pcm |
| D. | single tone modulation |
| Answer» A. fsk | |
| 62. |
Commercial Frequency deviation of FM is |
| A. | 70 khz |
| B. | 75 khz |
| C. | 80 khz |
| D. | 65 khz |
| Answer» B. 75 khz | |
| 63. |
The colour of an object is decided by |
| A. | the reflected colour |
| B. | the wavelength transmitted through it |
| C. | reflected colour for opaque object and wavelength transmitted through it for transparent objects |
| D. | none of the above |
| Answer» C. reflected colour for opaque object and wavelength transmitted through it for transparent objects | |
| 64. |
In Pulse Code Modulation system |
| A. | large bandwidth is required |
| B. | quantising noise can be overcome by companding |
| C. | quantising noise can be reduced by decreasing the number of standard levels |
| D. | suffers from the disadvantage of its incompatibly with tdm |
| Answer» A. large bandwidth is required | |
| 65. |
Which of the following statements is correct? |
| A. | convex lens has positive focal power and concave lens have negative focal power |
| B. | convex lens has negative focal power and concave lens have positive focal power |
| C. | all lens have positive focal power |
| D. | all lens have negative focal power |
| Answer» A. convex lens has positive focal power and concave lens have negative focal power | |
| 66. |
In Modulation, “carrier” is |
| A. | resultant wave |
| B. | speech voltage to be transmitted |
| C. | voltage with constant frequency, phase or amplitude |
| D. | voltage for which frequency, phase or amplitude is varied |
| Answer» D. voltage for which frequency, phase or amplitude is varied | |
| 67. |
To eliminate ghosts in the picture |
| A. | use a longer transmission line |
| B. | connect a booster |
| C. | change the antenna orientation of location |
| D. | twist the transmission line |
| Answer» C. change the antenna orientation of location | |
| 68. |
The frequency range of 300 kHz to 3000 kHz is known as |
| A. | low frequency |
| B. | medium frequency |
| C. | high frequency |
| D. | very high frequency |
| Answer» B. medium frequency | |
| 69. |
Which of the following does not cause losses in optical fibre cables? |
| A. | stepped index operation |
| B. | impurities |
| C. | microbending |
| D. | attenuation in glass |
| Answer» A. stepped index operation | |
| 70. |
For a low level AM system, the amplifiers modulated stage must be |
| A. | linear devices |
| B. | harmonic devices |
| C. | class c amplifiers |
| D. | non-linear devices |
| Answer» A. linear devices | |
| 71. |
A telephone channel requires a bandwidth of about |
| A. | 1 khz |
| B. | 3 khz |
| C. | 10 khz |
| D. | 50 khz |
| Answer» B. 3 khz | |
| 72. |
For a given carrier wave, maximum undistorted power is transmitted when value of modulation is |
| A. | 1 |
| B. | 0.8 |
| C. | 0.5 |
| D. | 0 |
| Answer» A. 1 | |
| 73. |
As per Shannon-Hartley theorem, a noise less Gaussian channel has |
| A. | zero capacity |
| B. | infinite capacity |
| C. | small capacity |
| D. | none of the above |
| Answer» B. infinite capacity | |
| 74. |
DVD uses |
| A. | laser beam for both recording and playback |
| B. | laser beam for recording and video head for playback |
| C. | video head for recording and laser beam for playback |
| D. | none of the above |
| Answer» A. laser beam for both recording and playback | |
| 75. |
Fourier analysis indicate that a square wave can be represented as |
| A. | a fundamental sine wave and odd harmonics |
| B. | a fundamental sine wave and even harmonics |
| C. | a fundamental sine wave and harmonics |
| D. | fundamental and subharmonic sine waves |
| Answer» A. a fundamental sine wave and odd harmonics | |
| 76. |
FM transmitting and receiving equipment as compared to AM equipment is |
| A. | costly |
| B. | cheaper |
| C. | almost equally costly |
| D. | none of the above |
| Answer» A. costly | |
| 77. |
An audio signal (say from 50 Hz to 10000 Hz) is frequency translated by a carrier having a frequency of 106 Hz. The values of initial (without frequency translation) and final (after frequency translation) fractional change in frequency from one band edge to the other are |
| A. | 200 and 1.01 |
| B. | 200 and 10.01 |
| C. | 200 and 100.1 |
| D. | 200 and 200 |
| Answer» A. 200 and 1.01 | |
| 78. |
If in a broadcasting studio, a 1000 kHz carrier is modulated by an audio signal of frequency range 100-5000 kHz, the width of channel is __________ kHz. |
| A. | 5 |
| B. | 4.9 |
| C. | 995 |
| D. | 10 |
| Answer» D. 10 | |
| 79. |
Which one of the following is analog? |
| A. | pcm |
| B. | pwm |
| C. | delta modulation |
| D. | differential pcm |
| Answer» B. pwm | |
| 80. |
The disadvantage of FM over AM is that |
| A. | high output power is needed |
| B. | high modulating power is needed |
| C. | noise is very high for high frequency |
| D. | large bandwidth is required |
| Answer» D. large bandwidth is required | |
| 81. |
Which of the following is a digital modulation technique? |
| A. | pcm |
| B. | psk |
| C. | dm |
| D. | all |
| Answer» B. psk | |
| 82. |
Which of the following is used to generate PDM? |
| A. | free running multi-vibrator |
| B. | monostable multi-vibrator |
| C. | jk flip-flop |
| D. | schmitt trigger |
| Answer» B. monostable multi-vibrator | |
| 83. |
SSB can be generated by |
| A. | filter method |
| B. | phase cancellation method |
| C. | good attenuation characteristics |
| D. | all of the above |
| Answer» D. all of the above | |
| 84. |
A zero mean white Gaussian noise is passed through an ideal low pass filter of bandwidth 10 kHz. The output of the samples so obtained would be |
| A. | correlated |
| B. | statistically independent |
| C. | uncorrelated |
| D. | orthogonal |
| Answer» B. statistically independent | |
| 85. |
What is the purpose of peak clipper circuits in radio transmitters? |
| A. | to prevent overmodulation |
| B. | to reduce bandwidth |
| C. | to increase bandwidth |
| D. | to regulate oscillator i/p voltage |
| Answer» A. to prevent overmodulation | |
| 86. |
In case of low level amplitude modulation system, the amplifiers following the modulated stage must be |
| A. | class c amplifiers |
| B. | linear devices |
| C. | non-linear devices |
| D. | harmonic devices |
| Answer» B. linear devices | |
| 87. |
Under ordinary circumstances, impulse noise can be reduced in |
| A. | fm only |
| B. | am only |
| C. | both am and fm |
| D. | none of the above |
| Answer» A. fm only | |
| 88. |
In case of frequency modulation, modulating voltage remains constant if the modulating frequency is lowered, then |
| A. | amplitude of distant sidebands decreases |
| B. | amplitude of distant sidebands increases |
| C. | amplitude of distant sidebands remains constant |
| D. | amplitude of distant sidebands first increases, then decreases |
| Answer» B. amplitude of distant sidebands increases | |
| 89. |
If sampling is done at the rate of 10 kHz. The bandwidth required is |
| A. | 35 khz |
| B. | 70 khz |
| C. | 10 khz |
| D. | 1280 khz |
| Answer» A. 35 khz | |
| 90. |
It is found that a ship to ship communication suffers from fading. This can be avoided by using |
| A. | space diversity |
| B. | frequency diversity |
| C. | broad band antenna |
| D. | directional antenna |
| Answer» B. frequency diversity | |
| 91. |
In practical commercial FM system, channel bandwidth is |
| A. | 150 khz |
| B. | 100 khz |
| C. | 88 mhz |
| D. | 108 mhz |
| Answer» A. 150 khz | |
| 92. |
In EM waves, polarization |
| A. | is always vertical in an isotropic medium |
| B. | is caused by reflection |
| C. | is due to transverse nature of waves |
| D. | results from longitudinal nature of waves |
| Answer» C. is due to transverse nature of waves | |
| 93. |
The maximum power output of a standard A earth station over the total band allocated to satellite communication is about |
| A. | 0.5 kw |
| B. | 8 kw |
| C. | 20 kw |
| D. | 50 kw |
| Answer» A. 0.5 kw | |
| 94. |
PAM stands for |
| A. | pulse analogue modulation |
| B. | phase analogue modulation |
| C. | pulse amplitude modulation |
| D. | phase amplitude modulation |
| Answer» C. pulse amplitude modulation | |
| 95. |
The characteristic impedance of a twin wire feeder used for TV signals is about |
| A. | 1000 ohm |
| B. | 500 ohm |
| C. | 300 ohm |
| D. | 100 ohm |
| Answer» C. 300 ohm | |
| 96. |
In a FM receiver, amplitude limiter |
| A. | amplifiers low frequency signals |
| B. | reduces the amplitude of signals |
| C. | eliminates any change in amplitude of received fm signals |
| D. | none of the above |
| Answer» C. eliminates any change in amplitude of received fm signals | |
| 97. |
A buffer amplifier is |
| A. | a double-tuned amplifier |
| B. | a high gain d.c. amplifier |
| C. | a cathode follower stage |
| D. | none of the above |
| Answer» B. a high gain d.c. amplifier | |
| 98. |
Leak type bias is used in plate modulated class C amplifier to |
| A. | increase the bandwidth |
| B. | prevent over modulation |
| C. | prevent excessive grid current |
| D. | prevent tuned circuit damping |
| Answer» C. prevent excessive grid current | |
| 99. |
The direction of rotation of a CD is |
| A. | clockwise |
| B. | anticlockwise |
| C. | clockwise or anticlockwise depending on frequency of data stored |
| D. | mostly anticlockwise but some times clockwise |
| Answer» B. anticlockwise | |
| 100. |
One of the advantages of base modulation over collector modulation of a transistor class C amplifier is |
| A. | improved efficiency |
| B. | better linearity |
| C. | high power output per transistor |
| D. | the lower modulating power requirement |
| Answer» D. the lower modulating power requirement | |
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