Question

If a signal is sampled at a sampling rate of 0.2 ms, then its sampling frequency is ____________kHz.

Hint:

Sampling frequency is the reciprocal of the sampling interval: f_s = 1/delta_t.

Answer 1

Correct Answer: 5

A different way to reach the same number is to count samples per unit time directly rather than inverting the interval algebraically. If one sample is taken every 0.2 ms, then in 1 second (=1000 ms) the number of samples recorded is:

\[ \text{samples per second} = \frac{1000\ \text{ms}}{0.2\ \text{ms/sample}} = 5000\ \text{samples/s} \]

Since "samples per second" (Hz) is precisely the definition of sampling frequency, this directly gives

\[ f_s = 5000\ \text{Hz} = 5\ \text{kHz} \]

which agrees with the reciprocal-of-interval method. This unit-counting approach is a useful cross-check in digital seismic acquisition, where sample intervals are often quoted in milliseconds (e.g. 2 ms, 4 ms) and need quick conversion to the corresponding sampling/Nyquist frequency.

\(\boxed{f_s = 5\ \text{kHz}}\)