Problem involving slits, diffraction, and incident angle.


by nobb
Tags: angle, diffraction, incident, involving, slits
nobb
nobb is offline
#1
Aug29-06, 08:01 PM
P: 33
Hi.
I am a bit confused with this question:

A plane wave of 400-nm light is incident on a 25-(mu) m slit in a screen, as shown in the figure below. At what incident angle will the first null of the diffraction pattern be on a line perpendicular to the screen? (picture is attached).

Do I use the formula wavelength=(dSinA)/n ? I am a bit unsure what the "first null" refers to and how this should be taken into account into my formula. Is the first null refering to "n"?

Help would be appreciated. Thank you.
Attached Thumbnails
problem.JPG  
Phys.Org News Partner Science news on Phys.org
SensaBubble: It's a bubble, but not as we know it (w/ video)
The hemihelix: Scientists discover a new shape using rubber bands (w/ video)
Microbes provide insights into evolution of human language
andrevdh
andrevdh is offline
#2
Aug30-06, 03:58 AM
HW Helper
P: 1,449
I would think that the first null will refer to the position next to the central maximum where destructive interference occurs "for the first time". The formula you are referring to gives the angles at which minima will be located behind the screen. So the first minima will occur at n = 1.


Register to reply

Related Discussions
Trig problems (Interference/diffraction and slits)) Introductory Physics Homework 3
incident light angle brightness General Physics 4
Solar Cells... incident angle of radiation. General Physics 1
Angle of Incident Problem Introductory Physics Homework 1
Multiple slits diffraction Introductory Physics Homework 2