An equilateral prism and air have a critical angle of 45°. If the incoming ray is perpendicular to the refracting surface ______?

ایک مساوی پرزم اور ہوا کا 45 ڈگری کا نازک زاویہ ہوتا ہے۔ اگر آنے والی شعاع ریفریکٹنگ سطح پر کھڑی ہے تو یہ _____؟

It keeps reflecting from all the three sides of the prism and never emerges out

It gets reflected from second and third surfaces and emerges from the first surface

It is reflected from the second surface and emerges perpendicular from the third surface

None of these

Explanation

Total Internal Reflection (TIR): Since the critical angle is 45°, and the incident ray is perpendicular to the first surface, it enters without deviation and strikes the second surface at 60° (greater than 45°), causing TIR.

Emergence: After reflecting from the second surface, the ray reaches the third surface at 30°, which is less than the critical angle, so it emerges perpendicularly from the third surface.