double slit diffraction problems young’s double slit formula: answers 1) in a double slit interference experiment, the distance betwe
Double Slit Diffraction Problems Young’s Double Slit Formula:
Answers
1) In a double slit interference experiment, the distance between the
slits is 0.0005m and the screen is 2 meters from the slits. Yellow
light from a sodium lamp is used and it has a wavelength of 5.89 x 10-7
m. Show that the distance between the first and second fringes on the
screen is 0.00233 m. (Fringe is another word for bright spot).
d=
=5.89 x 10-7 m
m=1, = 0.675º
m=2. = 0.135 º
(Height of lower fringe) = 0.0236m
(Height of upper fringe) = 0.0472m
Difference between two fringe locations. (For small angles –
approximately evenly spaced – You could take distance to third fringe
and divide by 3).
2) With two slits spaced 0.2mm apart, and a screen at a distance of l=1m,
the third bright fringe is found to be displaced h=7.5mm from the
central fringe. Show that the wavelength, , of the light used
is .
Step 1, Given l, h, find the angle by using trigonometry.
Step 2. Now that is known, you can use the formula with m=3 to
find the wavelength.
3. Two radio towers are broadcasting on the same frequency. The signal
is strong at A, and B is the first signal minimum. If d = 6.8 km, L =
11.2 km, and y = 1.73 km, what is the wavelength of the radio waves to
the nearest meter?
First find the angle:
Find the wavelength
4a. Water waves of wavelength of 5.44 meters are incident upon a
breakwater with two narrow openings separated by a distance 247
meters. To the nearest thousandth of a degree what is angle
corresponding to the first wave fringe maximum?
5. In a double-slit experiment it is found that blue light of
wavelength 467 nm gives a second-order maximum at a certain location
on the screen. What wavelength of visible light would have a minimum
at the same location?
Two different experiments with the same slit spacing, d, and same
angle, θ.
6. Find the distance between adjacent dark spots from a double slit
diffraction pattern if the wavelength of light is 500 nm, the distance
between the slits is 1 mm, and the distance from the slit to the
screen is 2 m.
Since spots are almost uniformly spaced, the distance between dark
spots is the same as the distance between bright spots. So just find
distance to first bright spot.
-First find the angle:
-Now use that angle to find the height of the first bright spot