100 kHz sinewave contaminating a signal sampled at 48 kHz If sampling at a rate of 48 kHz, with no anti-aliasing filter on the input, and the input signal is contaminated by a 100 kHz sine, at what frequency would the sinewave signal appear in the output spectrum?
In your case, since 100kHz is more than twice 48 kHz, it will be folded twice in the sampled version, then there are two pairs of positions: +/-4 KHz and +/- 44Khz.