Pressure at a depth h in a liquidद्रव में गहराई h पर दाब

NCERT Fig 9.3 · interactive diagram

Parts and their functions

• Liquid at rest, density ρ (विराम में द्रव, घनत्व ρ) — Pressure depends only on depth, not on the shape of the vessel (hydrostatic paradox).
• Imaginary column, area A (काल्पनिक स्तंभ, क्षेत्रफल A) — In equilibrium: (P − Pₐ)A = mg = ρhAg.
• Atmospheric pressure Pₐ (वायुमंडलीय दाब Pₐ) — 1 atm = 1.013 × 10⁵ Pa (76 cm of mercury).
• Depth h (गहराई h) — Every 10 m of water adds about 1 atm.
• Absolute pressure P (निरपेक्ष दाब P) — P = Pₐ + ρgh. The excess ρgh is the gauge pressure.
• Weight of the column (स्तंभ का भार) — mg = ρ(hA)g, acting down.

Original diagram drawn by Simple Learning Hub, based on NCERT Fig 9.3. Report a mistake