NEET Physics: critical velocity Practice Questions
15 free multiple-choice questions on critical velocity (Properties of Solids and Liquids) for NEET Physics, each with the correct answer and a step-by-step explanation. Attempt a question, then reveal the solution to check your reasoning.
Practice thousands more NEET questions in the app →Q1. Which property is directly related to the resistance encountered when a fluid moves at or above its critical velocity?
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Correct answer: B — Viscosity
Resistance to flow is governed by viscosity. Above the critical velocity, the flow behavior is highly dependent on the fluid's viscous properties.
Q2. When considering the properties of liquids, the critical velocity often serves as a boundary condition for macroscopic behavior. If the flow velocity is precisely at the critical velocity, what is the state of the flow?
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Correct answer: A — The flow is stable and transitional
The critical velocity represents the exact transition point; thus, at this velocity, the flow is in a transitional, stable state just before instability sets in.
Q3. The critical velocity is a parameter that helps determine the onset of flow instability. Which term best describes the flow regime before this critical velocity is reached?
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Correct answer: C — Laminar regime
The flow regime characterized by smooth, orderly movement before instability sets in is known as the Laminar regime.
Q4. The critical velocity in fluid dynamics primarily defines the transition between which two types of flow regimes?
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Correct answer: B — Laminar flow and turbulent flow
Critical velocity is crucial in flow analysis, defining the point where the flow transitions from smooth, orderly Laminar flow to chaotic, irregular Turbulent flow.
Q5. The concept of critical velocity is most relevant when considering the transition between:
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Correct answer: D — Linear flow and turbulent flow
Critical velocity defines the boundary where the flow regime transitions, specifically between stable laminar flow and potentially unstable/turbulent flow.
Q6. For a specific type of fluid, the critical velocity is proportional to which physical property?
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Correct answer: A — The fluid's surface tension
The relationship often involves balancing dynamic pressures against surface tension effects, making surface tension a key determinant in the critical velocity calculation.
Q7. If the critical velocity for a specific flow condition is exceeded, what is the immediate consequence typically observed?
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Correct answer: B — Flow instability
Exceeding the critical velocity usually leads to flow instability, often resulting in turbulence or chaotic flow patterns.
Q8. In the context of fluid mechanics, the critical velocity is primarily determined by the balance between which two forces?
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Correct answer: A — Inertial forces and surface tension
Critical velocity arises from the interplay between inertial forces (related to velocity) and surface tension forces that govern the stability of the flow.
Q9. What physical phenomenon is typically associated with the concept of critical velocity in fluid systems?
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Correct answer: D — Turbulent flow onset
Critical velocity often marks the transition point where a flow transitions from smooth (laminar) to chaotic (turbulent) behavior in a fluid system.
Q10. If a fluid is moving at a velocity just below its critical velocity, the flow profile tends to be highly ordered. If the velocity increases slightly above this critical velocity, what is the immediate consequence observed in the flow field?
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Correct answer: A — The flow exhibits flow separation
Exceeding the critical velocity causes the flow to become unstable, resulting in flow separation or the initiation of turbulent flow patterns.
Q11. If the velocity of a fluid is exactly equal to the critical velocity, what is the state of the flow considered to be?
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Correct answer: D — The transition point between laminar and turbulent flow
The critical velocity marks the exact boundary or transition point between the orderly laminar flow regime and the chaotic turbulent flow regime.
Q12. If the velocity of a fluid exceeds its critical velocity in a given setup, what is the immediate physical consequence often observed?
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Correct answer: D — Flow separation
Exceeding the critical velocity often results in flow separation or cavitation, as the flow demands exceed the system's capacity to maintain smooth flow.
Q13. Which physical quantity is primarily used to define the critical velocity threshold for flow instability in a fluid?
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Correct answer: A — Viscosity of the fluid
The critical velocity for flow instability is fundamentally related to the balance between inertial forces and viscous forces, making the viscosity of the fluid a key determining factor in the instability condition.
Q14. The critical velocity in fluid flow generally marks the point where the flow transitions from a smooth, orderly state to a disturbed, chaotic state. This transition is primarily governed by which physical parameter?
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Correct answer: B — Viscosity of the fluid
The transition between laminar flow (orderly) and turbulent flow (chaotic) is fundamentally dependent on the balance between inertial forces and viscous forces, which is dictated by the fluid's viscosity.
Q15. Which property of the fluid is most significantly involved in determining the magnitude of the critical velocity?
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Correct answer: B — Density and Viscosity
The critical velocity is intrinsically dependent on the physical properties of the fluid, primarily its density and viscosity, as these govern the inertia and viscous forces involved.
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