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 |