Bernoulli’s theorem and applications MCQs With Answer

Bernoulli’s theorem and applications MCQs With Answer

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Bernoulli’s theorem and applications MCQs With Answer

Bernoulli’s theorem is a fundamental principle in fluid dynamics that links pressure, velocity and elevation in a flowing fluid. For B.Pharm students, understanding Bernoulli’s principle, Bernoulli equation, continuity equation and their limitations is essential for drug delivery systems, nebulizers, inhalers, atomizers, venturi masks and intravenous flow devices. This topic covers energy conservation in incompressible flow, Venturi and Pitot devices, flow measurement, pressure drops, and practical pharmaceutical applications like aerosol generation and spray drying. Mastery of these concepts helps in designing and troubleshooting medical and laboratory fluid systems. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. What is the core statement of Bernoulli’s theorem for an incompressible, non-viscous fluid along a streamline?

  • Sum of pressure, kinetic and potential energy per unit volume is constant
  • Pressure increases with increase in velocity
  • Viscous losses can be ignored only at high Reynolds number
  • Temperature remains constant along the streamline

Correct Answer: Sum of pressure, kinetic and potential energy per unit volume is constant

Q2. Which of the following is NOT an assumption of the classical Bernoulli equation?

  • Flow is steady
  • Flow is incompressible
  • Significant viscous dissipation occurs
  • Flow is along a streamline

Correct Answer: Significant viscous dissipation occurs

Q3. In Bernoulli’s equation, which term represents kinetic energy per unit volume?

  • p (pressure)
  • ρgh (potential energy head)
  • ½ρv² (dynamic pressure)
  • Q/A (volumetric flow rate divided by area)

Correct Answer: ½ρv² (dynamic pressure)

Q4. The continuity equation for incompressible flow states which relationship?

  • ρ1A1v1 = ρ2A2v2
  • A1v1 = A2v2
  • p1 + p2 = constant
  • v1 + v2 = constant

Correct Answer: A1v1 = A2v2

Q5. A Venturi meter in a pharmaceutical fluid line is used to measure what?

  • Temperature of the fluid
  • Flow rate using pressure difference
  • Chemical composition of solution
  • Viscosity directly

Correct Answer: Flow rate using pressure difference

Q6. What does a Pitot tube measure in a flow used in inhaler testing?

  • Static pressure only
  • Dynamic pressure only
  • Total (stagnation) pressure from which velocity can be derived
  • Temperature and humidity

Correct Answer: Total (stagnation) pressure from which velocity can be derived

Q7. Which pharmaceutical device uses the Venturi effect for aerosol generation?

  • Tablet press
  • Jet nebulizer
  • Centrifuge
  • Lyophilizer

Correct Answer: Jet nebulizer

Q8. According to Bernoulli’s principle, when fluid velocity increases in a constriction, what happens to static pressure?

  • Static pressure increases
  • Static pressure decreases
  • Static pressure remains unchanged
  • Temperature must increase

Correct Answer: Static pressure decreases

Q9. Which condition invalidates the simple Bernoulli equation for many real pharmaceutical flows?

  • Low Reynolds number laminar flow
  • Negligible viscosity
  • Significant viscous energy losses and turbulence
  • Incompressible Newtonian fluid

Correct Answer: Significant viscous energy losses and turbulence

Q10. For flow through a horizontal constriction, Bernoulli predicts pressure change mainly due to changes in what?

  • Elevation head
  • Velocity head
  • Temperature gradient
  • Chemical potential

Correct Answer: Velocity head

Q11. In the Bernoulli equation p + ½ρv² + ρgh = constant, what does ρgh represent?

  • Viscous head loss
  • Kinetic energy
  • Potential energy due to elevation
  • Compressibility correction

Correct Answer: Potential energy due to elevation

Q12. How does Bernoulli’s principle help explain aerosol formation in medical atomizers?

  • By increasing fluid temperature to vaporize liquid
  • By converting pressure energy into kinetic energy to shear liquid into droplets
  • By filtering out large particles mechanically
  • By changing chemical composition

Correct Answer: By converting pressure energy into kinetic energy to shear liquid into droplets

Q13. Which parameter must be measured in a Venturi meter to calculate volumetric flow?

  • Pressure difference between throat and inlet
  • Temperature at outlet
  • Viscosity of the fluid only
  • Density gradient along the pipe

Correct Answer: Pressure difference between throat and inlet

Q14. When applying Bernoulli to blood flow in a narrowed artery, what pharmaceutical concern is highlighted?

  • Change in blood chemistry
  • Pressure drop leading to possible tissue hypoperfusion
  • Increase in blood temperature
  • Solid deposition of drug particles

Correct Answer: Pressure drop leading to possible tissue hypoperfusion

Q15. Bernoulli’s principle assumes no work is done on or by the fluid. Which device violates this assumption?

  • Open-channel flow with no pumps
  • Pump-driven infusion system
  • Gravity-fed reservoir to syringe
  • Simple Venturi constriction

Correct Answer: Pump-driven infusion system

Q16. In practice, how are viscous losses added to Bernoulli’s equation for engineering calculations?

  • They are ignored always
  • By adding a head loss term (hf) to the equation
  • By changing fluid density only
  • By assuming flow is compressible

Correct Answer: By adding a head loss term (hf) to the equation

Q17. Which device uses the Venturi effect to entrain air into a liquid drug for aerosol delivery?

  • Autoclave
  • Venturi nebulizer/aspirator
  • Tablet coating drum
  • High-shear mixer

Correct Answer: Venturi nebulizer/aspirator

Q18. A reduction in cross-sectional area in a pipe leads to which of the following according to continuity and Bernoulli?

  • Velocity decreases and pressure increases
  • Velocity increases and pressure decreases
  • Both velocity and pressure increase
  • Both velocity and pressure decrease

Correct Answer: Velocity increases and pressure decreases

Q19. Which nondimensional number indicates whether viscous or inertial forces dominate, affecting Bernoulli applicability?

  • Prandtl number
  • Reynolds number
  • Biot number
  • Damköhler number

Correct Answer: Reynolds number

Q20. In inhaler design, Bernoulli effects are used to optimize what property?

  • Tablet hardness
  • Particle size distribution of aerosol
  • pH of formulation
  • Solubility of API

Correct Answer: Particle size distribution of aerosol

Q21. For compressible gases at high speeds, Bernoulli’s equation must be modified because of what?

  • Heat transfer effects only
  • Density changes with pressure and temperature
  • Viscosity becomes zero
  • Surface tension dominates

Correct Answer: Density changes with pressure and temperature

Q22. Cavitation in pumps or atomizers can occur when Bernoulli-predicted pressure falls below what?

  • Static pressure at inlet
  • Vapor pressure of the liquid
  • Atmospheric pressure only
  • Hydrostatic pressure at bottom of tank

Correct Answer: Vapor pressure of the liquid

Q23. Which measurement in a flow system provides the static pressure used in Bernoulli calculations?

  • Open tube perpendicular to flow
  • Tube aligned with flow capturing stagnation point
  • Thermocouple reading
  • Mass spectrometer output

Correct Answer: Open tube perpendicular to flow

Q24. The term “head” in Bernoulli contexts (e.g., velocity head) refers to what?

  • Energy per unit mass expressed as equivalent height
  • Physical height of the laboratory
  • Number of layers in tablet coating
  • Time required for flow stabilization

Correct Answer: Energy per unit mass expressed as equivalent height

Q25. When using Bernoulli’s equation to size tubing for an IV line, which property of fluid is most critical?

  • Solubility
  • Density and viscosity affecting flow and head loss
  • Color of the solution
  • Electrical conductivity

Correct Answer: Density and viscosity affecting flow and head loss

Q26. Which is a common real-world modification to Bernoulli’s ideal equation for engineering pipelines?

  • Subtracting a frictional head loss term
  • Adding thermal expansion term
  • Changing gravity sign
  • Replacing velocity head with pressure head

Correct Answer: Subtracting a frictional head loss term

Q27. In a spray dryer, Bernoulli principles assist in controlling what key process parameter?

  • Evaporation temperature only
  • Air velocity and pressure to control droplet breakup
  • Chemical reaction rate
  • Solid particle crystallinity

Correct Answer: Air velocity and pressure to control droplet breakup

Q28. When applying Bernoulli between two points one above the other, which term accounts for elevation difference?

  • ½ρv²
  • ρgh
  • p
  • hf

Correct Answer: ρgh

Q29. Which type of flow line is most appropriate for applying Bernoulli directly without large corrections?

  • Highly turbulent flow with many fittings
  • Straight smooth pipe with steady incompressible flow
  • Two-phase flow with bubbles
  • Flow with chemical reactions releasing heat

Correct Answer: Straight smooth pipe with steady incompressible flow

Q30. The Bernoulli constant along a streamline is affected by which of the following?

  • Frictional energy losses
  • No external forces
  • Conservative body forces only
  • Isolated chemical reactions

Correct Answer: Frictional energy losses

Q31. In many respiratory devices, reducing downstream pressure by increasing velocity is used to do what?

  • Warm the gas mixture
  • Induce entrainment of ambient air or liquid
  • Increase solubility of drug
  • Change pH

Correct Answer: Induce entrainment of ambient air or liquid

Q32. Which instrument uses Bernoulli principle to measure fluid velocity in medical device testing?

  • Gas chromatograph
  • Pitot-static tube
  • HPLC pump
  • pH meter

Correct Answer: Pitot-static tube

Q33. Bernoulli predicts that at the throat of a Venturi, static pressure is lower. This lower pressure can be used to:

  • Heat the fluid
  • Draw or entrain another fluid into the stream
  • Increase viscosity of the mixture
  • Sterilize the liquid

Correct Answer: Draw or entrain another fluid into the stream

Q34. For liquid drug formulation flows where viscosity dominates, which modification is essential?

  • Ignore viscosity and use basic Bernoulli
  • Include viscous head loss and laminar flow corrections
  • Assume compressible fluid behavior
  • Use ideal gas law

Correct Answer: Include viscous head loss and laminar flow corrections

Q35. In Bernoulli contexts, what is dynamic pressure?

  • Pressure due to fluid motion equal to ½ρv²
  • Hydrostatic pressure ρgh
  • Ambient atmospheric pressure
  • Pressure measured only at inlet

Correct Answer: Pressure due to fluid motion equal to ½ρv²

Q36. Which application in pharmaceutics uses low-pressure regions created by high-speed jets to aerosolize liquids?

  • Tablet compression
  • Jet nebulization and atomization
  • Freeze drying
  • Chromatographic separation

Correct Answer: Jet nebulization and atomization

Q37. In a horizontal pipe with incompressible flow, if pressure at section 1 is greater than section 2, what can be inferred about velocities?

  • Velocity at section 1 is higher than at section 2
  • Velocity at section 2 is higher than at section 1
  • Velocities are equal always
  • Cannot infer without temperature data

Correct Answer: Velocity at section 2 is higher than at section 1

Q38. Bernoulli’s equation is most accurate when applied along which path in a flow field?

  • Between two arbitrary points in different streamlines without correction
  • Along a single streamline where assumptions hold
  • Across shock waves in compressible flow
  • Within regions of strong turbulence

Correct Answer: Along a single streamline where assumptions hold

Q39. Why is Bernoulli’s theorem important for designing inhaler mouthpieces?

  • To change chemical stability of drug
  • To optimize airflow and shear for desired aerosol particle size
  • To control tablet disintegration
  • To maintain constant temperature only

Correct Answer: To optimize airflow and shear for desired aerosol particle size

Q40. When using Bernoulli to estimate pressure drop across an orifice, which additional factor improves accuracy?

  • Neglecting discharge coefficient
  • Using an empirical discharge coefficient
  • Assuming incompressible gas behavior always
  • Ignoring downstream conditions

Correct Answer: Using an empirical discharge coefficient

Q41. The Venturi mask for oxygen therapy uses Bernoulli principle to:

  • Heat incoming oxygen
  • Mix oxygen with entrained room air to deliver controlled FiO2
  • Filter out pathogens
  • Generate aerosols from liquids

Correct Answer: Mix oxygen with entrained room air to deliver controlled FiO2

Q42. In a Bernoulli analysis, adding a pump between two points typically does what to the energy balance?

  • Removes energy from the fluid
  • Adds mechanical work (energy) to the fluid
  • Leaves the energy unchanged
  • Changes fluid density only

Correct Answer: Adds mechanical work (energy) to the fluid

Q43. Which phenomenon in sprays is directly influenced by local pressure drops predicted by Bernoulli?

  • Crystallinity of solids
  • Droplet breakup and atomization intensity
  • Covalent bond formation
  • pH stabilization

Correct Answer: Droplet breakup and atomization intensity

Q44. For measuring flow in a pharmaceutical duct using Bernoulli-based devices, calibration accounts for which real effect?

  • Perfect inviscid behavior
  • Frictional losses and geometry-dependent discharge coefficients
  • Nozzle always ideal
  • Zero pressure gradients

Correct Answer: Frictional losses and geometry-dependent discharge coefficients

Q45. Which scenario would demand a compressible form of Bernoulli for accurate prediction?

  • Low-speed water flow in tubing
  • High-speed gas flow approaching Mach 0.3 or above
  • Slow laminar oil flow
  • Steady incompressible liquid flow

Correct Answer: High-speed gas flow approaching Mach 0.3 or above

Q46. In lab-scale nebulizer testing, using Bernoulli and continuity helps predict what practical outcome?

  • Chemical degradation of API
  • Aerosol output rate and droplet velocity
  • pH changes during nebulization
  • Tablet dissolution time

Correct Answer: Aerosol output rate and droplet velocity

Q47. Bernoulli’s theorem links which forms of energy in a fluid element?

  • Chemical and nuclear energy
  • Pressure energy, kinetic energy and potential energy
  • Electrical and magnetic energy
  • Thermal and reaction energy

Correct Answer: Pressure energy, kinetic energy and potential energy

Q48. Why are empirical discharge coefficients used with Venturi and orifice meters in pharmacy equipment?

  • To ignore fluid density
  • To correct for non-ideal flow separation and viscous effects
  • To change chemical composition
  • To control temperature only

Correct Answer: To correct for non-ideal flow separation and viscous effects

Q49. If a pharmaceutical pump creates a high-velocity jet into a liquid pool, Bernoulli predicts low pressure at the jet core which may cause what?

  • Instant chemical equilibrium
  • Cavitation and vapor bubble formation if pressure < vapor pressure
  • Increase in viscosity to infinity
  • Solid formation from solution

Correct Answer: Cavitation and vapor bubble formation if pressure < vapor pressure

Q50. When teaching Bernoulli to B.Pharm students, which practical lab exercise best illustrates the principle?

  • Measuring tablet tensile strength
  • Using a Venturi tube or Pitot tube to measure flow and compare with Bernoulli predictions
  • Performing an HPLC assay
  • Conducting dissolution testing only

Correct Answer: Using a Venturi tube or Pitot tube to measure flow and compare with Bernoulli predictions

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