Physics · Class 11 · Chapter 9
Mechanical Properties of Fluids
12 lessons 103 min 2 simulations
Liquids and gases flow, so a single set of ideas covers both. This chapter starts with fluids at rest (pressure, Pascal's law, pressure growing with depth, barometers and manometers, hydraulic machines), moves to fluids in motion (streamlines, the equation of continuity, Bernoulli's principle, Torricelli's law, dynamic lift), then to the friction inside real fluids (viscosity, Stokes' law, terminal velocity) and ends at the surface of a liquid (surface tension, angle of contact, excess pressure in drops and bubbles, capillary rise).
What the exam asks
NEET tests P = P_a + ρgh and gauge pressure, the hydraulic-lift ratio A₂/A₁ with the matching distance ratio, U-tube problems with two liquids, Av = constant, Bernoulli with Torricelli's √(2gh), lift on a wing from ΔP × area, η from Stokes' law and terminal velocity v_t ∝ a², excess pressure 2S/r for a drop but 4S/r for a soap bubble, and capillary rise h = 2S cos θ/(ρga). Marks slip when diameter is used as radius, when gauge and absolute pressure are mixed, when a soap bubble gets 2S/r, and when the direction of viscosity change with temperature is reversed for gases.
Lessons
12 lessons · 103 min
1Fluids and pressureNCERT §9.1, §9.27 min2Pascal's law and pressure with depthNCERT §9.2.1, §9.2.27 min3Atmospheric and gauge pressureNCERT §9.2.37 min4Hydraulic machinesNCERT §9.2.411 min 1 sim5Streamline flow and continuityNCERT §9.37 min6Bernoulli's principleNCERT §9.4, §9.4.110 min 1 sim7Dynamic liftNCERT §9.4.26 min8Viscosity and Stokes' lawNCERT §9.5, §9.5.18 min9Surface energy and surface tensionNCERT §9.6, §9.6.1, §9.6.27 min10Angle of contact, drops and bubblesNCERT §9.6.3, §9.6.47 min11Capillary riseNCERT §9.6.57 min12Chapter reviewMust-know facts, traps and formulas19 min