New Cartesian sign convention for spherical mirrorsगोलीय दर्पणों के लिए नई कार्तीय चिह्न परिपाटी

NCERT Fig 9.9 · interactive diagram

Parts and their functions

• Pole P = origin (ध्रुव P = मूल बिंदु) — All distances are measured from the pole (optical centre for a lens).
• Positive x-direction (धनात्मक x-दिशा) — Distances measured in the direction of incident light (to the right) are positive.
• Negative x-direction (ऋणात्मक x-दिशा) — Distances measured against the incident light (to the left) are negative. So u is negative.
• Heights above the axis: + (अक्ष के ऊपर ऊँचाई: +) — Upward, perpendicular to the principal axis: positive (erect object or image).
• Heights below the axis: − (अक्ष के नीचे ऊँचाई: −) — Downward: negative. An inverted real image has negative height.
• Object (बिंब) — Always placed to the left of the mirror.
• Incident light (आपतित प्रकाश) — Falls on the mirror from the left side.
• Mirror (principal axis = x-axis) (दर्पण (मुख्य अक्ष = x-अक्ष)) — The principal axis is taken as the x-axis of the coordinate system.

Original diagram drawn by Simple Learning Hub, based on NCERT Fig 9.9. Report a mistake