A cathode-ray oscilloscope (c.r.o.) shows a waveform that represents a sound wave. To find the frequency of the sound wave, which section of the displayed waveform should be measured, and which c.r.o. setting has to be known?
- Aamplitude; time-base
- Bamplitude; Y-gain
- Cwavelength; time-base
- Dwavelength; Y-gain