64. For a global coverage, the minimum number of satellites required is
A. ten
B. one
C. three
D. two

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65. When carrier wave is modulated at 100%, its power is increased by ? percent.
A.100
B.150
C.50
D.0

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66. An RF amplifier stage in a radio receiver noise-limited sensitivity.
A. improves
B. deteriorates
C. has no effect on
D. Amplifiers

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67. Medium waves in day time are propagated via
A. ionosphere
B. ground
C. troposphere
D. A is

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68. On a clear sky day, the atmosppheric radio noise is strongest
A. during morning hours
B. around mid-day
C. during nights
D. in the afternoon

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69.  VHF radio signals are propagated
A. via the ionosphere
B. along the ground
C. through the troposphere
D. microwave channels

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70. The atmospheric radio noise
A. increases as the frequency increases
B. decreases as the frequency increases
C. remains constant with change in frequency
D. none of above

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