I have been given an audio file (sine wave) 1000Hz as an input to my FFT algorithm. I have got 8192 power spectrum samples in a array.

What is the best and easiest way to check whether my output is right or wrong?

If I give a silent audio file then the output is zero for all samples. In a sine wav the o/p increases from 20 (0th sample) to 26059811 (743rd sample) and decreases gradually to 40.

If I get an idea of the output range then I can prove technically whether the FFT is working.

Any ideas would be helpful.

Refer to this link for any technical doubts.