Refraction through a prismप्रिज़्म से अपवर्तनRefraction through a prism

NCERT Fig 9.21 · Class 12 Physics · Chapter 9 · interactive diagram

Parts and what they mean

• Triangular glass prism ABC (त्रिभुजाकार काँच प्रिज़्म ABC) — Two refracting faces AB and AC meet at the angle of the prism A.
• Incident ray PQ (आपतित किरण PQ) — Meets face AB at angle of incidence i.
• Refracted ray QR (inside) (अपवर्तित किरण QR (अंदर)) — Bends towards the normal at Q (angle r₁) and meets face AC at r₂. Geometry gives r₁ + r₂ = A.
• Emergent ray RS (निर्गत किरण RS) — Leaves face AC at the angle of emergence e, bent towards the base.
• Normals at Q and R (Q और R पर अभिलंब) — They meet at N inside the prism; quadrilateral AQNR has two right angles, so ∠A + ∠QNR = 180°.
• Angle of deviation δ (विचलन कोण δ) — Angle between the emergent ray and the original direction of the incident ray: δ = (i − r₁) + (e − r₂) = i + e − A.
• Angle of incidence i (आपतन कोण i) — At face AB.
• r₁ (r₁) — Angle of refraction at face AB.
• r₂ (r₂) — Angle of incidence (glass → air) at face AC.
• Angle of emergence e (निर्गमन कोण e) — Angle of refraction at face AC.
• Angle of the prism A (प्रिज़्म कोण A) — Angle between the two refracting faces (60° here).
• Q (Q) — Point of incidence on face AB.
• R (R) — Point of emergence on face AC.

Original diagram drawn by Simple Learning Hub, based on NCERT Fig 9.21. Report a mistake