1. How many octaves higher is a 7600-Hz sine wave than a 2100-Hz sine wave?
2. A lowpass Butterworth filter has a corner frequency of 1 kHz and a roll-off of 24 dB per octave in the stopband. If the output amplitude of a 3-kHz sine wave is 0.10 V, what will be the output amplitude of a 20-kHz sine wave if the input amplitudes are the same?