TG EAMCET 2 May 2025 Shift 1 Paper

µ=√2,A=90∘
For total internal reflection
‌sin‌iC‌=‌

1

µ

=‌

1

√2

=sin‌45∘
‌∴‌iC‌=45∘
For total internal reflection to occur at the second face, the angle of incidence at the second face ( r2 ) must be greater than or equal to the critical angle. To ensure total internal reflection, we consider the limiting case where
r2=θc=45∘
The angle of the prism is related to the angles of refraction at the two faces by
A=r1+r2
Since A=90∘ and r2=45∘
‌90∘=r1+45∘
‌r1=90∘−45∘=45∘
Applying Snell's law at the first face,
µ‌air ‌‌‌sin‌i=µ‌prism ‌‌‌sin‌r1
1⋅sin‌i=√2sin‌45∘
sin‌i=√2⋅‌

1

√2

=1=sin‌90∘
∴‌‌i=90∘