190. An amplitude modulated wave is
A. the product of the carrier and the modulating wave
B. sum of the carrier and its product with modulating signal
C. the sum of the carrier and the modulating wave
D. the difference between the carrier and the modulating wave

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191. The modulation index of an amplitude modulated wave is changed from 0 to 1. The transmitted power is
A. doubled
B. halved
C. increased by 50 percent
D. unchanged

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192. A SSB (Single-side band) signal contains 3 kW. The power content of the carrier is
A. 0 kW
B. 1 kW
C. 2 kW
D. 3 kW

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193.  If a signal band limited to fm is sampled at a rate less than 2 fm, the reconstructed signal will
A. be samller in amplitude
B. have higher frequencies suppressed
C. be distorted
D. none of the above

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194.  A transistor is basically an amplifying device for
A. current
B. voltage
C. power
D. none of the above

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195. If the output power of radio receiver is doubled, the volume is increased by
A. ?3 dB
B. 1 dB
C. 2 dB
D. 3 dB

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196. In a radio the IF amplifier
A. can be tuned to various station frequencies
B. is tuned above the station's incoming frequency
C. is fixed-tuned to one particular frequency
D. amplifiers the output of loacal oscillator

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