Question

Using δ = i + e - A for equilateral prism obtain an equation for refractive index (n) of material of the prism.

Answer 1

The nature of deviation of the equilateral prism is:

δ = i + e - A

Since it is the equilateral prism hence angle will be 60 degree = A

δ = i + e - 60

60 + δ = I + e, if i = e

Then,

60 + δ = 45 + 45

Hence. δ = 30 degree

Refractive index,

m = sin A + δm / sin A/2

m = sin45/sin30 = root 2 = 1.414

Answer 2

Answer~

in attachment

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hope it helps ;)