Wave properties and wave graphsEdexcel A-Level Physics: Mind map

Exam questions on Wave properties and wave graphs

1. A student displays the signal from a microphone on an oscilloscope. The time base is set to 0.50 ms per division and the Y-gain to 2.0 V per division. One complete cycle of the trace spans 4.0 divisions horizontally, and the distance from a trough to the next crest spans 5.0 divisions vertically. The speed of sound in air is 340 m s⁻¹.
   Calculate the wavelength of the sound wave.2 marks
2. A technician sends a sound wave along a long air-filled tube using a loudspeaker. She is interested in how the pressure of the air and the displacement of the air molecules from their equilibrium positions vary as a progressive wave passes along the tube.
   Explain how the wave transfers energy along the tube although there is no net movement of air along it.2 marks
3. A student determines the speed of sound in air. A loudspeaker driven by a signal generator at 2000 Hz is placed at one end of a metre rule. Two microphones are connected to the two channels of an oscilloscope. Microphone 1 stays next to the loudspeaker and microphone 2 is moved slowly along the rule. The student records each position of microphone 2 at which the two traces are exactly in phase. The distance between the first and the sixth in-phase positions is 0.850 m.
   Calculate the speed of sound in air from the student's results.3 marks