Ray diagram: concave mirror (object beyond C)
Real, inverted, diminished image between F and C.
Step 1 — Study the figure
Cover the label key on the image, name each numbered part, then check the explanations below.
Step 2 — Diagram details for students
What this diagram shows
For a concave mirror with object beyond C, the image is real, inverted, and diminished between F and C. Ray diagrams plus Cartesian sign convention are both needed for numericals. State nature, position, and size together in answers.
Numbered parts — mark & remember
Match each number on the figure with the meaning below. Say the function aloud once.
1 Object beyond C
The object stands outside the centre of curvature on the principal axis. This position determines a diminished real image. Mark object distance carefully for formula work.
2 Pole / Focus / Centre
Pole P is the mirror centre point, F is focus, and C is centre of curvature. For small apertures, R = 2f so C is twice as far as F. These points are mandatory labels in ray diagrams.
3 Image between F and C
The image forms between focus and centre of curvature. It is real (can be caught on screen), inverted, and smaller than the object. Write all three properties in one sentence.
4 Ray construction
Use two standard rays: one parallel to axis through F after reflection, and one through C reflecting back on itself. Their intersection gives image location. Neat arrows show incident and reflected directions.
How to read this figure
- Identify object position relative to F and C first.
- Then predict image nature from the standard table.
- Use mirror formula with Cartesian signs for numericals.
Redraw for board marks
- Draw concave mirror, axis, and points P, F, C.
- Place object beyond C and draw two rays.
- Mark image between F and C with inverted arrow.
Board answer tip: Draw the ray diagram and write: real, inverted, diminished, between F and C.
Exam tips — don’t lose marks
- Real images are inverted for these spherical mirror cases in basic tables.
- Sign convention mistakes cause most numerical errors.
- Always state nature + position + size.