PhysicsLAB Worksheet
Double Slits
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Refer to the following information for the next eight questions.

Light with wavelength 435 nm is incident on a pair of slits.
 
 
Point P is located in the center of the first order maximum (B1) at an angular deviation of 4º.
What is the EPD between two rays, one emanating from the top slit and the other from the bottom slit, as they reach point P?



 
What is the separation between the slits? 

If the screen is 200 cm from the slits, what is the linear deviation from the middle of the central maximum to the middle of B1 as measured along the screen? 

What is the angular deviation to the center of B2? 

What would be the angular deviation to the center of B10? 

What would be the angular deviation to the center of B20? 

We are now going to use the same apparatus to determine the wavelength of a new light source. If the second maximum of the new light source exactly matches the location of B3 from our original light, what is the wavelength of the new source? 

If the apparatus were to be submerged in water, at what angle would we observe B10 if we use our original light? 

Refer to the following information for the next two questions.

Monochromatic light in incident on a pair of slits, S1 and S2, that are separated by 4.0 x 10-6 meters (d).
 
 
On a screen 1 meter away (L) each bright fringe (A, B, and C) is separated from its neighbor by 0.17 meters.
What is the wavelength of the incident light?
 
What is the highest order bright fringe that could be viewed on the screen?
 
Refer to the following information for the next two questions.

When yellow light having a wavelength of 5.8 x 10-7 meters, shines through two slits 2 x 10-4 meters apart, an interference pattern is formed on a screen 3 meters away.
 
What is the linear deviation along the screen between the middle of the third order bright and the middle of the central maximum?
 
If a grating having 14,700 lines per inch were used instead of the original two slits, what would be the new linear deviation along the screen between the middle of the third order bright and the middle of the central maximum? 

Refer to the following information for the next question.

In a Young’s double slit experiment, the second and higher order bright bands can overlap.
The fourth order band of which wavelength would occur at the same location as the second order band of 760 nm?
 
Refer to the following information for the next question.

A student performs an experiment similar to Young’s Double Slit Experiment. Coherent light passes through two narrow slits and produces a pattern of alternating bright and dark lines on a screen.
Which of the following would cause the bright lines on the screen to move further apart?
 
  1. Decrease the distance between the slits by moving them closer together.
  2. Decrease the distance from the slits to the screen.
  3. Decrease the wavelength of the incident light.
 
 







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