Difraction and stationary wave

[saltrock]

a)Sodium light produces two types of wavelength 589.0nm and 589.6nm.the two emissions have similar intensities.explain if you'd expect the presence of two wavelengths to be a problem in obserbing a clear interference pattern

b)A loud speaker is hung on the top of a clamp facing vertically downwards on a bench.The loudspeaker is turned on and the stationary wave pattern is formed.Explain why the contrast between maxima and minima becomes less pronounced as the microphone is raised further from the surface of the bench.

If you can giveme some hint i'd be very grateful.

 

[ponjavic]

I'd guess the sodium emissions would overlap each other looking as it was one?

 

[wais]

a) The presence of two wavelengths in sodium light would not necessarily be a problem in observing a clear interference pattern. Diffraction occurs when light passes through a narrow slit or aperture, causing the light to spread out and interfere with itself, creating a pattern of bright and dark bands. This pattern is dependent on the wavelength of the light and the size of the slit. Therefore, the two wavelengths of sodium light would produce two separate interference patterns, but they would still be distinguishable from each other. The pattern may appear slightly more complex due to the presence of two wavelengths, but it would not be a problem in observing a clear interference pattern.

b) As the microphone is raised further from the surface of the bench, the contrast between maxima and minima in the stationary wave pattern becomes less pronounced. This is because the distance between the loudspeaker and the microphone increases, resulting in a decrease in the intensity of the sound waves reaching the microphone. As a result, the amplitude of the stationary waves decreases, making it more difficult to distinguish between the maxima and minima. Additionally, as the microphone is raised, it may also pick up other interfering sounds or vibrations, further reducing the contrast between the maxima and minima.