Graphical Inverse Relationship for single slit

This forum made possible through the generous support of SDN members, donors, and sponsors. Thank you.

SaintJude

Full Member
10+ Year Member
Joined
Jan 4, 2012
Messages
1,479
Reaction score
5
So in a single slit set up in which diffraction occurs. Kaplan says that as the "slit becomes narrower, the central maximum becomes winder."

Which graph accurately show the relationship? I don't have then answer.

The linear inverse
220px-Simple_inverse_relationship_chart.svg.png


The curved inverse
image002.gif


I think it's the inverse curved graph b/c the the location of the dark fringes is given by the formula asinθ = nλ = constant.
And sinθ is directly proportional proportional to the width of the central maxima
So asinθ = constant are represented by the inverse curve graph. 👍👎?
 
That's correct, it will be inversely proportional. The distance from the center to the first minimum (dark spot) is L*tan θ, where L is the distance between the screen and the slit. From a sin θ = λ we have sin θ = λ/a and for small θ sin θ = tan θ. That means that the distance to the first dark spot is y=L*tan θ=L*sin θ=Lλ/a or a*y=Lλ=const.
 
Top