Sample the message signal with sampling frequency, Fs = 8kHz
Calculate the folding frequency.
Folding frequency is the maximum frequency that can be represented uniquely by the sampled signals.
For the frequency, F1 = 5kHz, observe that the frequency F1 is greater than the folding frequency. Aliasing will occur as it is higher than folding frequency and frequencies up to folding frequency can only be recovered. Particular frequency will be changed as,
Now, 5kHz signal frequency will be changed by aliasing effect.