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⚛️ Physics  ·  Mechanical Properties of Fluids  ·  NEET & JEE

The buoyant force on a submerged object depends on:

Answer: The volume of the object (not its weight or density).

  • A The volume of the object (not its weight or density)
  • B The weight of the object in air before submersion
  • C The chemical composition or material of the object
  • D Only the geometric shape of the object, regardless of size

Correct answer: A. The volume of the object (not its weight or density)

Explanation: Buoyant force = ρ_fluid × V<sub>submerged</sub> × g. It depends on the density of the fluid and the volume submerged, NOT on the object weight, material, or shape.

Continuity Equation: Narrow Pipe → Faster FlowA₁, v₁ (wide, slow)A₂, v₂ (narrow, fast)A₁v₁ = A₂v₂ (continuity)Smaller area → higher speed → (by Bernoulli) LOWER pressure

Since the same volume of fluid must pass every cross-section per second (continuity), the fluid speeds up where the pipe narrows; Bernoulli's equation then says this faster-moving fluid has lower pressure - the principle behind a venturi meter and an aircraft wing's lift.

Concept context

Pressure, buoyancy, Bernoulli equation, viscosity, and surface tension.

Read the full Mechanical Properties of Fluids notes →