What a prism, a convex lens and a concave mirror do to a plane wavefrontप्रिज़्म, उत्तल लेंस और अवतल दर्पण समतल तरंगाग्र के साथ क्या करते हैंWhat a prism, a convex lens and a concave mirror do to a plane wavefront

NCERT Fig 10.7 · Class 12 Physics · Chapter 10 · interactive diagram

Parts and what they mean

• Thin prism (पतला प्रिज़्म) — Light is slower in glass. The lower part of the wavefront crosses the thickest glass and is delayed most.
• Incident plane wavefront (आपतित समतल तरंगाग्र) — A plane wave coming from the left.
• Emerging (tilted) wavefront (निर्गत (झुका) तरंगाग्र) — Because the lower part lags, the wavefront tilts and the wave (ray) bends towards the base of the prism.
• Convex lens (उत्तल लेंस) — Thickest at the centre, so the central part of the wavefront is delayed most.
• Converging spherical wavefronts (अभिसारी गोलीय तरंगाग्र) — The emerging wavefront has a depression at the centre: it becomes spherical and converges to the focus F.
• Focus F (lens) (फोकस F (लेंस)) — Point where the wave converges. Time taken from object to image is the same along every ray.
• Concave mirror (अवतल दर्पण) — Reflects a plane wave into a spherical wave converging to its focus.
• Reflected converging wavefronts (परावर्तित अभिसारी तरंगाग्र) — Travel back towards F (to the left).
• Focus F (mirror) (फोकस F (दर्पण)) — Focal point of the concave mirror, f = R/2.

Original diagram drawn by Simple Learning Hub, based on NCERT Fig 10.7. Report a mistake