User:Inconspicuum/Physics (A Level)/Waves Questions

What is a wave?

 * 1) What is wave?
 * 2) Through what medium are sound waves propagated?
 * 3) What aspects of the behaviour of light make it look like a wave?
 * 4) What aspects of the behaviour of light make it look like a particle?
 * 5) Consider the diagram on the right. White light is partially reflected by the transparent material. Some of the light, however, is refracted into the transparent material and reflected back by the opaque material. The result is two waves travelling in the same place at the same time at the same polarisation(the light is not a single beam). Why does, say, the red light disappear? (Variations on this question are popular with examiners.)
 * 6) What is the wavelength of green light?
 * 7) The lowest frequency sound wave humans can hear has a frequency of approximately 20Hz. Given that the speed of sound in air is 343ms-1, what is the wavelength of the lowest frequency human-audible sound?

Phasors

 * 1) A sine wave with wavelength 0.1m travels through a given point on the surface of the sea. A phasor arrow representing the effect of this wave on this point rotates 1000°. How many wavelengths have gone past in the time taken for the phasor to rotate this much?
 * 2) A sine wave has a maximum amplitude of 500nm. What is its amplitude when the phasor has rotated 60° from its start position?
 * 3) Two waves have a phase difference of 45°. When the first wave is at its minimum amplitude of -0.3m, what is the total amplitude of the superposed waveforms?

Standing Waves

 * 1) The air in a 3m organ pipe is resonating at the fundamental frequency. Organ pipes are effectively open at both ends. What is the wavelength of the sound?
 * 2) A string is vibrating at the second harmonic frequency. How many wavelengths long is the standing wave created?
 * 3) Express, in terms of λ, the length of a pipe which is closed at one end, where λ is the length of one wave at the fundamental frequency.

Young's Slits

 * 1) A 2-slit experiment is set up in which the slits are 0.03 m apart. A bright fringe is observed at an angle 10° from the normal. What sort of electromagnetic radiation was being used?
 * 2) Light, with a wavelength of 500 nm, is shone through 2 slits, which are 0.05 m apart. What are the angles to the normal of the first three dark fringes?
 * 3) Some X-rays, with wavelength 1 nm, are shone through a diffraction grating in which the slits are 50 μm apart. A screen is placed 1.5m from the grating. How far are the first three light fringes from the point at which the normal intercepts the screen?

Diffraction

 * 1) What is the width of the central bright fringe on a screen placed 5m from a single slit, where the slit is 0.01m wide and the wavelength is 500nm?