Concave mirror: real image (ray diagram)अवतल दर्पण: वास्तविक प्रतिबिंब (किरण आरेख)Concave mirror: real image (ray diagram)
NCERT Fig 9.5 · Class 12 Physics · Chapter 9 · interactive diagram
Parts and what they mean
- Concave mirror (अवतल दर्पण) — A reflecting surface that is part of a hollow sphere, silvered on the outside so it reflects from the inside (curved in towards the object). Converging.
- Principal axis (मुख्य अक्ष) — The line through the pole P and the centre of curvature C.
- Pole P (ध्रुव P) — Geometric centre of the mirror surface. All distances are measured from P.
- Principal focus F (मुख्य फोकस F) — Rays parallel to the axis meet here after reflection (concave) or seem to come from here (convex). PF = f = R/2.
- Centre of curvature C (वक्रता केंद्र C) — Centre of the sphere of which the mirror is a part. PC = R. A ray through C hits the mirror along the normal and retraces its path.
- Object AB (वस्तु AB) — Height h is positive (above the axis). Object distance u is negative (it is opposite to the incident light, on the left).
- Image A′B′ (real, inverted) (प्रतिबिंब A′B′ (वास्तविक, उलटा)) — Reflected rays really meet here, so it can be caught on a screen. v is negative (same side as the object) and h′ is negative (below the axis), so m = −v/u is negative.
- Ray 1: parallel to the axis (किरण 1: अक्ष के समांतर) — After reflection it passes through the focus F.
- Ray 2: through C (किरण 2: C से होकर) — Strikes the mirror along the normal (the radius), so it comes straight back along the same line.
- Ray 3: through F (किरण 3: F से होकर) — After reflection it travels parallel to the principal axis.
Original diagram drawn by Simple Learning Hub, based on NCERT Fig 9.5. Report a mistake