Nyquist rate determination and oversampling [duplicate]

1. What advantages does the oversampling approach have over standard sampling at the Nyquist rate?
2. What could be a possible drawback of oversampling?
3. Why is Nyquist rate twice?
4. What will happen when sampling rate is greater than Nyquist rate?

What advantages does the oversampling approach have over standard sampling at the Nyquist rate?

The Nyquist rate is defined as twice the bandwidth of the signal. Oversampling is capable of improving resolution and signal-to-noise ratio, and can be helpful in avoiding aliasing and phase distortion by relaxing anti-aliasing filter performance requirements.

What could be a possible drawback of oversampling?

Oversampling unnecessarily increases the ADC output data rate and creates setup and hold-time issues, increases power consumption, increases ADC cost and also FPGA cost, as it has to capture high speed data.

Why is Nyquist rate twice?

If the signal contains high frequency components, we will need to sample at a higher rate to avoid losing information that is in the signal. In general, to preserve the full information in the signal, it is necessary to sample at twice the maximum frequency of the signal. This is known as the Nyquist rate.

What will happen when sampling rate is greater than Nyquist rate?

It is the critical rate of sampling. If the signal xt is sampled above the Nyquist rate, the original signal can be recovered, and if it is sampled below the Nyquist rate, the signal cannot be recovered.