This learning object is based on the concept of double-split interference.

2. Question 1
You view an interference pattern of blue light on a screen. Choice the
statement that correctly describes all the ways that you could change the
conditions of the set-up to view an interference pattern with fringes that
are closer together.
a) Move the slits farther from the screen, increase the spacing of the slits,
or change the light to orange?
b) Move the slits closer to the screen, increase the spacing of the slits, or
change the light to violet.
c) Move the slits closer to the screen, increase the spacing of the slits
or change the light to red.
d) Move the slits farther to the screen, decrease the spacing of the
splits, or change the light to violet.

3. Question 2
D = 12 cm
Label angle θ and find the number of
bright fringes on the screen.
θ
θΛ = 450 nm
S1
S2
d
y = 0.750 cm
m=0
m=1
Assume that the screen extends
a long ways in each direction.

4. Solution 1
Answer b
To decrease distance between the fringes you can move the
slits closer to the screen, increase the spacing of the slits, or
decrease the wavelength of light.

5. Solution 2
tan θ=(7.50*10^-3 m) / (0.120 m)
= 0.0625
θ= 3.58°
d = mλ/sinθ = 1(4.50*10^-7) / (sin(3.58°)) = 7.21*10^-6
m = (d sinθ)/(λ) = (7.21*10^-6)(sin(3.58°)) / (4.50*10^-7)
= 1
2 bright fringes in total.