Sampling pure tone sine waves [closed]

1. What happens if you sample at Nyquist frequency?
2. What happens to the signal if it is sampled below Nyquist limit?
3. What happens if you sample too slow?
4. Why is it necessary to limit the band of a signal before performing sampling?

What happens if you sample at Nyquist frequency?

It can be seen that by sampling at the Nyquist rate, we can get the frequency information about the signal. However, to faithfully reconstruct the signal, we have to increase the sampling rate even more.

What happens to the signal if it is sampled below Nyquist limit?

As the sampling frequency decreases, the signal separation also decreases. When the sampling frequency drops below the Nyquist rate, the frequencies will crossover and cause aliasing.

What happens if you sample too slow?

If the sample rate of the data acquisition system is too slow relative to the frequency of the signal, your measurement literally falls apart.

Why is it necessary to limit the band of a signal before performing sampling?

Band limiting ensures that the original input signal can be reconstructed exactly from the ADC's output samples when a sampling frequency (f_s) of twice the information bandwidth of the analog input signal is used (Nyquist sampling).