In the given figure, ∠1,∠2,∠3 and ∠4, respectively are-A. angle of em…

The correct answer is Option (3) → B, D, C, A

Each angle at a refracting surface is measured from the normal, and the deviation is the angle between the directions of the incident ray and the emergent ray. Reading the angles from the figure:

∠1 lies between the incident ray and the normal at face PQ, outside the prism, so it is the angle of incidence (B).

∠2 lies between the incident ray produced forward and the emergent ray produced backward, so it is the angle of deviation (D).

∠3 lies between the ray inside the glass and the normal at face PQ, so it is the angle of refraction (C).

∠4 lies between the emergent ray and the normal at face PR, outside the prism, so it is the angle of emergence (A).

So ∠1, ∠2, ∠3 and ∠4 are B, D, C, A.

NCERT (2026-27):
Refraction Through a Prism – “Figure 9.21 shows the passage of light through a triangular prism ABC. The angles of incidence and refraction at the first face AB are \( i \) and \( r_1 \), while the angle of incidence (from glass to air) at the second face AC is \( r_2 \) and the angle of refraction or emergence \( e \). The angle between the emergent ray RS and the direction of the incident ray PQ is called the angle of deviation, \( \delta \).”