211.  A heterodyne frequency changer is called a
A. frequency translator
B. mixer
C. modulator
D. any of the above

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212.  The total power content of an AM signal with 100 percent modulation is 1200W. Power being transmitted at each sideband is
A. 200 W
B. 300 W
C. 400 W
D. 800 W

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213.  Which of the following is the main reason for double spotting in receivers?
A. High selectivity of he receiver
B. Inadequate image-frequency rejection
C. High gain of IF amplifier
D. Low sensitivity of RF amplifier

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214.  Modulated carrier power in FM modulating signal power.
A. decreases with
B. increases with
C. is independent of
D. none of the above

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215. high frequencies noise assumes great importance at
A. Short
B. Johnson
C. Flicker
D. Transit-time

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216.  If the modulation index of an AM wave is changed from 0 to 1 the transmitted power
A. will remain unchanged
B. will decrease by 50 percent
C. will increase by 50 percent
D. will increase by 200 percent

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217. A constant-amplitude modulated frequency of 500 kHz causes a carrier to vary between 8798.5 MHz and 8801.5 MHz. the modulation index is
A.2
B.3
C.4
D.6

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