Quiz6
Problem 1
In a twoslit interference experiment, the path length to a certain point
P
on the
screen differs for one slit in comparison to other by
1
.25
λ
.
(a) What is the phase difference between the two waves arriving at point
P
?
(b) Determine the intensity at
P
, expressed as a function of the maximum intensity
I
0
on the screen.
Solution
: (Ch 34, problem # 20)
a)
The phase difference is given in Eq. 344. We are given the path length
difference, dsinθ.
.
5
.
2
25
.
1
2
sin
2
π
δ
θ
=
=
⇒
=
d
b)
The intensity is given by Eq. 346.
(
29
0
2
0
2
0
500
.
0
25
.
1
cos
2
cos
I
I
I
I
=
=
=
Problem 2
Light of wavelength 690 nm passes through two narrow slits 0.66 mm apart. The screen
is 1.6 m away. A second source of unknown wavelength produces its second order fringe
1.23 mm closer to the central maximum than the 690nm light.
What is the wavelength of the unknown light? (Hint: Use approximation of small angles
s
in
θ≈
tan
θ≈θ
)
Solution:
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview.
Sign up
to
access the rest of the document.
 Winter '08
 staff
 Physics, Light, Wavelength, phase difference

Click to edit the document details