Ten questions. The result tells you which lessons you may skip.
At one instant, one speaker alone would give a pressure variation of \(+0.05\,\text{Pa}\) at a point. A second speaker alone would give \(-0.05\,\text{Pa}\). The pressure variation at the point is
Two speakers in phase emit sound of wavelength \(0.5\,\text{m}\). At a point the path difference is \(0.125\,\text{m}\). The phase difference of the two waves there is
Two speakers in phase play the same tone. At a point where the path difference is \(3\lambda/2\), the listener hears
Two speakers \(2.0\,\text{m}\) apart play a tone of wavelength \(0.5\,\text{m}\) in phase. On a line \(10\,\text{m}\) away, the first quiet spot is about how far from the centre line?
Noise-cancelling headphones make a quiet sound at the ear by
The sliding U-tube of a Quincke's tube is pulled out by \(x\). The path difference changes by
In a Quincke's tube, two successive minima are \(8.5\,\text{cm}\) apart on the slide. With sound at \(340\,\text{m/s}\), the frequency of the source is
A compression travels along a pipe and reflects from its closed end. What comes back?
The open end of a pipe is
A boy shouts towards a hill and hears the echo \(0.6\,\text{s}\) later. With sound at \(340\,\text{m/s}\), the hill is