Choose the right answer 1- An envelope detector is considered as: i) A synchronous demodulator An asynchronous demodulator iii) None of the above 2- The bandwidth of an audio signal is i) 8 KHz ii) 30 KHz iii) 4 KHz i None of the above 3. In analog QAM, i) Two (or more) signals share the same frequency band by occupying different time slots. ii) Two signals with identical information content are multiplexed using the same carrier. iii) Two signals share the same time slot by modulating carriers of different frequency. Two signals share the same frequency band by modulating orthogonal carrier. 4- For the same available transmitted bandwidth, the maximum number of signals that could be multiplexed using analog modulation techniques is obtained when the modulation is: i) FDM-FM ii) FDM-DSBSC iii) FDM-VSB iv) FDM-DSBLC None of the above