Refraction of Light in a laser beam

[sci0x]

Question
A laser beam travels from air into a symmetrical prism at right angles close to its upper edge. The refractive index of the prism material n = 1.4 and its angle is 30 degrees.

i)
Calculate the critical angle for the prism-air interface.
Possible Answer:
Critical angle = arcsine(1/n)
arcsine(1/1.4)
= 45.585 degrees

ii)
After passing through the prism, what angle does the beam make with the incident ray?
Possible Answer:
Sine Angle = (n of prism)(Sine30)/n of air
= ((1.4)(Sin30))/1.0
Sine Angle = 0.7
Angle = 44.427 degrees

Are these correct?

 

[vaishakh]

n = sin(A/2 + x/2)/sin(A/2). Here critical angle is x. 2 is correct.