Which of the following is not a digital-to-analog conversion?

In ............, the amplitude of the carrier signal is varied to create signal elements. Both frequency and phase remain constant.

In ........., the frequency of the carrier signal is varied to represent data. Both peak amplitude and phase remain constant.

In .............., the phase of the carrier is varied to represent two or more different signal elements. Both peak amplitude and frequency remain constant.

In ............ transmision, the carrier signal is modulated so that its amplitude varies with the changing amplitudes of the modulating signal.

In .......... transmission, the phase of the carrier signal is modulated to follow the changing voltage level (amplitude) of the modulating signal.

In .........., the peak amplitude of one signal level is 0, the other is the same as the amplitude of the carrier frequency.

How many carrier frequencies are used in BASK?

How many carrier frequencies are used in BFSK?

How many carrier frequencies are used in BPSK?