Is there something wrong with this? http://www.jiskha.com/display.cgi?id=1335108759 The part poorly defined is the "peak that is ...wide". The formula I gave you is the distance to the first minimum.
Some folks use the "width " of the peak to not the first minimum, but to the point where the peak has went down to the .707 RMS value.
When violet light of wavelength 415 nm falls on a single slit, it creates a central diffraction peak that is 8.80 cm wide on a screen that is 2.75 m away. How wide is the slit?
7 answers
I skipped over this question because I was not sure what was meant by width of the stripe. I think first minimum is most common.
The width of the central peak (max) is the distance between the first minima.
The equation for diffraction minima is
b•sinφ = k•λ.
k =1,
b = λ/sinφ.
From the geometry of diffraction pattern
tanφ =x1/L,
where x1 =8.8/2 = 4.4 cm =0.044 m is the distance between the center of diffraction pattern and the first min,
and L =2.75 m.
tan φ = 0.044/2.75=0.016.
sin φ = tan φ=0.016.
b = λ/sinφ = 415•10^-9/0.016 =
=2.59•10^-5 m =25.9 micrometers.
The equation for diffraction minima is
b•sinφ = k•λ.
k =1,
b = λ/sinφ.
From the geometry of diffraction pattern
tanφ =x1/L,
where x1 =8.8/2 = 4.4 cm =0.044 m is the distance between the center of diffraction pattern and the first min,
and L =2.75 m.
tan φ = 0.044/2.75=0.016.
sin φ = tan φ=0.016.
b = λ/sinφ = 415•10^-9/0.016 =
=2.59•10^-5 m =25.9 micrometers.
Thank you so much Elena! I forgot to divide 8.8 by two and, of course, kept getting double the answer which I knew was incorrect.
Anyone else from SF have to google this question, or was i the only one?
After 10 years and the question :
When violet light of wavelength 415 nm falls on a single slit, it creates a central diffraction
fringe that is 9.2 cm wide on a screen that is 2.55 m away. How wide is the slit?
Lmao still the same wording tho i dont understand it now
When violet light of wavelength 415 nm falls on a single slit, it creates a central diffraction
fringe that is 9.2 cm wide on a screen that is 2.55 m away. How wide is the slit?
Lmao still the same wording tho i dont understand it now
oh now i get it thanks elena