Question

rohit is trying to tune an instrument. he strikes a tuning fork and then plays a note that almost matches it. rohit hears the volume of the two waves beating, which sounds like \wah - wah - wah - wah.\ what is the cause of the beats? the two waves produced have different speeds. the two waves produced have different amplitudes. the two waves produced have different wavelengths. the two waves produced have different frequencies.

Explanation:

Beats occur when two waves of slightly different frequencies interfere. The volume variation (wah - wah sound) is due to constructive and destructive interference over time. Wave speed (in same medium) and amplitude don't cause beats. Wavelength difference (if speed same) implies frequency difference (since \(v = f\lambda\)), but the direct cause of beats is frequency difference.

Answer:

The two waves produced have different frequencies.