Need help with angle of incidence of light through a prism

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SUMMARY

The discussion centers on calculating the angle of incidence for light entering an equilateral 60° glass prism with a refractive index of 1.651 for violet light. The critical angle is determined to be 37.3°, indicating that total internal reflection occurs when the angle of incidence exceeds this value. Participants clarify the correct notation for the critical angle calculation and emphasize the importance of accurately defining the angle of incidence in relation to the normal of the surface. A ray diagram is also requested for validation, but it is noted that the initial submission was incorrect.

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batcave1985
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Homework Statement


The direction of the ray of light enters equilateral 60° glass prism normal to the surface as shown in attached image
refracted index of the prism material for the violet light is 1.651

(a) What is the angle of incidence on the surface A-B?
(b) Does total internal reflection occur?
(c) Draw a ray diagram to show how light passes through
the prism

Homework Equations


critical angle-----sin i c= 1/n


The Attempt at a Solution


My attempt
a) critical angle
sin= 1/1.651
= 37.3°
Not sure if its 90° for the incidence for side A-B

b) Total internal reflections occur because the angle of incidence is greater
then the critical angle

c) i also attached my attempt to the image.


thank you any help would be great
 

Attachments

  • prism attempt.jpg
    prism attempt.jpg
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The calculation seems correct, but the way you expressed it is confusing.
You wrote
"sin= 1/1.651
= 37.3°"

You should have written
"sin θc= 1/1.651
θc = 37.3°"
 
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dauto said:
The calculation seems correct, but the way you expressed it is confusing.
You wrote
"sin= 1/1.651
= 37.3°"

You should have written
"sin θc= 1/1.651
θc = 37.3°"

thank you any chance you can tell me if my ray diagram in the picture attached is correct?
 
batcave1985 said:
thank you any chance you can tell me if my ray diagram in the picture attached is correct?

No.

Note that the angle of incidence is defined as the angle the ray encloses with the normal of the surface.
At totalreflecton, the ray is reflected from the surface AB inside the prism, and is incident onto an other side, and then leaves the prism.

ehild
 

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