Chapter-9 Mechanical Properties of Fluids — Online MCQ Test
PHYSICS · Grade 11 · CBSE(NCERT)
Practice Chapter-9 Mechanical Properties of Fluids with a free chapter-wise online MCQ test.
This chapter covers: Pressure due to a fluid column - Pascal's law - Buoyancy - Streamline flow - Turbulent flow - Critical velocity - Bernoulli's principle - Viscosity - Stokes' law - Terminal velocit....
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter-9 Mechanical Properties of Fluids — Important Questions & Answers
What is the SI unit of pressure?
- A. Newton per square meter (N/m²) or Pascal (Pa)
- B. Dyne per square centimeter
- C. Kilogram per square meter
- D. Joule per cubic meter
Answer: A. Newton per square meter (N/m²) or Pascal (Pa)
The SI unit of pressure is Pascal (Pa), which is equivalent to Newton per square meter (N/m²).
The SI unit of pressure is Pascal (Pa), which is equivalent to Newton per square meter (N/m²).
State Pascal's Law.
- A. Pressure exerted on a confined fluid is transmitted undiminished in all directions
- B. The density of a fluid increases with depth
- C. The buoyant force equals half the weight of the displaced fluid
- D. Viscosity increases with temperature in all fluids
Answer: A. Pressure exerted on a confined fluid is transmitted undiminished in all directions
Pascal's Law states that pressure applied to an enclosed fluid is transmitted equally in all directions with the same magnitude.
Pascal's Law states that pressure applied to an enclosed fluid is transmitted equally in all directions with the same magnitude.
A hydraulic press applies Pascal's Law. If the input piston has area A₁ and output piston has area A₂ (where A₂ > A₁), and a force F₁ is applied to the input piston, what is the output force F₂?
- A. F₂ = F₁(A₂/A₁)
- B. F₂ = F₁(A₁/A₂)
- C. F₂ = F₁A₁A₂
- D. F₂ = F₁/(A₁A₂)
Answer: A. F₂ = F₁(A₂/A₁)
By Pascal's Law, pressure is constant: F₁/A₁ = F₂/A₂, so F₂ = F₁(A₂/A₁), giving mechanical advantage.
By Pascal's Law, pressure is constant: F₁/A₁ = F₂/A₂, so F₂ = F₁(A₂/A₁), giving mechanical advantage.
A spherical ball of density ρ_ball and radius r falls through a fluid of density ρ_fluid and viscosity η. Assuming Stokes' Law applies and terminal velocity is reached, the terminal velocity is proportional to which of the following?
- A. r² and (ρ_ball - ρ_fluid)
- B. r and η
- C. r⁻² and ρ_fluid
- D. r⁴ and (ρ_ball + ρ_fluid)
Answer: A. r² and (ρ_ball - ρ_fluid)
From mg = 6πηrv_t, we get v_t = [2r²g(ρ_ball - ρ_fluid)]/(9η), showing v_t ∝ r² and (ρ_ball - ρ_fluid).
From mg = 6πηrv_t, we get v_t = [2r²g(ρ_ball - ρ_fluid)]/(9η), showing v_t ∝ r² and (ρ_ball - ρ_fluid).
A student uses Bernoulli's equation to explain why a spinning cricket ball curves in flight. Which assumption in the standard derivation of Bernoulli's equation is violated in this scenario, making the simple analysis invalid?
- A. The assumption of inviscid (frictionless) flow; viscosity and boundary layer effects are crucial for the Magnus effect
- B. The assumption of incompressible flow
- C. The assumption that flow is irrotational
- D. The assumption that pressure is constant along a streamline
Answer: A. The assumption of inviscid (frictionless) flow; viscosity and boundary layer effects are crucial for the Magnus effect
Bernoulli's equation assumes inviscid flow. The Magnus effect (ball curving) arises from viscous effects creating an asymmetric boundary layer around the spinning ball, which simple Bernoulli analysis cannot explain.
Bernoulli's equation assumes inviscid flow. The Magnus effect (ball curving) arises from viscous effects creating an asymmetric boundary layer around the spinning ball, which simple Bernoulli analysis cannot explain.