• Support PF! Buy your school textbooks, materials and every day products Here!

A shaft of light pass through the prism

  • Thread starter thee
  • Start date
  • #1
5
0
A shaft of light passes through a prism with refracting angle [tex] \theta [/tex] and refractive index [tex] n [/tex]. Let [tex] \alpha [/tex] be the deviation angle of the shaft. Demonstrate that if the shaft of light passes through the prism symetrically the angle [tex] \alpha [/tex] is the least?
 

Answers and Replies

  • #2
335
4
thee said:
A shaft of light passes through a prism with refracting angle [tex] \theta [/tex] and refractive index [tex] n [/tex]. Let [tex] \alpha [/tex] be the deviation angle of the shaft. Demonstrate that if the shaft of light passes through the prism symetrically the angle [tex] \alpha [/tex] is the least?
The least in regards to what?

-Dan
 
  • #3
5
0
picture

I suppose that [tex] \beta [/tex] is the refracting angle

I think that it try to proove that [tex]\beta[/tex] is equal to [tex] \theta [/tex] angle [tex] \alpha [/tex] will become the least.
 

Attachments

  • #4
lightgrav
Homework Helper
1,248
30
"passes through symmetrically" means that the path inside the prism
is parallel to the face of the prism that isn't used as a window ...
that is, theta_glass on face 2 = - theta_glass on face 1.

You'll probably want to assume an "apex" angle for the prism
and recall that the interior angles in a triangle sum to 180,
to relate the theta_glass on face 2 to the theta_glass on face 1.

With the deflection angle as a function of theta_glass, set the derivitive =0.
 

Related Threads on A shaft of light pass through the prism

Replies
2
Views
196
Replies
6
Views
2K
  • Last Post
Replies
2
Views
588
  • Last Post
Replies
2
Views
1K
  • Last Post
Replies
1
Views
5K
  • Last Post
Replies
4
Views
8K
  • Last Post
Replies
1
Views
6K
Replies
1
Views
7K
Replies
3
Views
626
Replies
6
Views
6K
Top