Why can a prism separate white light into component colours while a plane glass slab cannot, even though both cause refraction?
منشور سفید روشنی کو رنگوں میں کیوں بانٹتا ہے جبکہ متوازی سطحوں والی شیشے کی سل ایسا نہیں کرتی، اگرچہ دونوں انکسار کرتے ہیں؟
Solution & explanation
Dispersion occurs in both: refractive index depends on wavelength. In a parallel slab, refraction at the second face reverses angular separation so emergent colours are parallel, though slightly displaced. A prism’s nonparallel faces produce different net angular deviations.
Independent study answer. Original textbook ↗ · English-medium printed page 86.