Turbines – principle, construction, working, uses, merits, demerits MCQs With Answer: Turbines convert fluid energy into mechanical power and are vital in pharmaceutical plants for steam generation, HVAC, compressed air systems, and process utilities. This concise, Student-friendly post explains the principle, construction, working, common types (steam, gas, hydraulic), applications in B.Pharm settings, and key merits and demerits such as efficiency, maintenance needs, and environmental considerations. The content is tailored for B.Pharm students, linking theory to practical uses like sterilization, process heating, and power backup. Clear keywords include turbines, steam turbine, gas turbine, impulse, reaction, efficiency, and maintenance. Now let’s test your knowledge with 50 MCQs on this topic.
Q1. What is the basic operating principle of a turbine?
- Conversion of heat to chemical energy
- Conversion of kinetic energy of fluid to mechanical work
- Conversion of electrical energy to potential energy
- Conversion of light energy to thermal energy
Correct Answer: Conversion of kinetic energy of fluid to mechanical work
Q2. Which of the following describes an impulse turbine?
- Fluid pressure drops continuously over the blades
- Fluid jets strike the rotor blades causing impulse
- Turbine operates only with liquids
- It requires axial flow only
Correct Answer: Fluid jets strike the rotor blades causing impulse
Q3. Which type of turbine is commonly used for high head hydroelectric applications?
- Kaplan turbine
- Francis turbine
- Pelton wheel
- Axial flow gas turbine
Correct Answer: Pelton wheel
Q4. In reaction turbines, where does the energy conversion primarily occur?
- Only in stationary nozzles
- Due to pressure drop across both fixed and moving blades
- Only in the rotor shaft
- By combustion inside the rotor
Correct Answer: Due to pressure drop across both fixed and moving blades
Q5. Which turbine type is best suited for low head, high flow hydraulic sites?
- Pelton turbine
- Francis turbine
- Kaplan turbine
- Impulse steam turbine
Correct Answer: Kaplan turbine
Q6. What is a key constructional component of all rotary turbines?
- Burner assembly
- Rotor with blades
- Electrolyte chamber
- Photovoltaic cells
Correct Answer: Rotor with blades
Q7. Which parameter measures how close a turbine’s performance is to the ideal reversible process?
- Mechanical advantage
- Specific speed
- Isentropic efficiency
- Thermal conductivity
Correct Answer: Isentropic efficiency
Q8. In a steam turbine used in a pharmaceutical plant, what is the typical downstream equipment?
- Reactor vessel
- Condenser
- Chromatography column
- Incubator
Correct Answer: Condenser
Q9. Cavitation is a major concern for which type of turbine?
- Gas turbine operating at high altitude
- Hydraulic turbines like Kaplan and Francis
- Steam turbines at low load
- Wind turbines at steady speed
Correct Answer: Hydraulic turbines like Kaplan and Francis
Q10. Specific speed of a turbine helps in selecting which aspect?
- Material composition
- Type and geometry of turbine (e.g., axial, radial, mixed)
- Electrical insulation class
- Lubrication oil grade
Correct Answer: Type and geometry of turbine (e.g., axial, radial, mixed)
Q11. Which nozzle type is commonly used in impulse turbines to form high-velocity jets?
- Diffuser
- Convergent-divergent (De Laval) nozzle
- Porous membrane nozzle
- Axial vane nozzle
Correct Answer: Convergent-divergent (De Laval) nozzle
Q12. What is the primary disadvantage of steam turbines in small-scale pharmaceutical plants?
- Low rotational speed
- High initial cost and complex maintenance
- Unable to use steam as energy source
- Noisy liquid handling
Correct Answer: High initial cost and complex maintenance
Q13. Which turbine feature reduces axial thrust and helps in rotor stability?
- Nozzle throat
- Balance piston or balance drum
- Cavitation plate
- Governor valve
Correct Answer: Balance piston or balance drum
Q14. What is the role of the governor in turbine systems?
- To cool the turbine blades
- To maintain constant rotational speed under load changes
- To chemically treat boiler feedwater
- To increase fuel calorific value
Correct Answer: To maintain constant rotational speed under load changes
Q15. Which turbine is characterized by adjustable blade pitch suited for variable flow?
- Pelton wheel
- Kaplan turbine
- Impulse steam turbine
- Fixed-blade Francis turbine
Correct Answer: Kaplan turbine
Q16. What is enthalpy drop across turbine stages indicative of?
- Heat loss to surroundings
- Work available per unit mass of fluid
- Mechanical friction only
- Electrical output directly
Correct Answer: Work available per unit mass of fluid
Q17. For gas turbines used in emergency power at a pharma facility, what fuel property is most critical?
- Viscosity
- Calorific value
- Surface tension
- Dielectric constant
Correct Answer: Calorific value
Q18. Which material property is most important for turbine blades exposed to steam at high temperatures?
- Electrical conductivity
- Creep resistance
- Optical transparency
- Magnetic susceptibility
Correct Answer: Creep resistance
Q19. Multistage steam turbines are used primarily to:
- Increase mechanical complexity for hobbyists
- Extract energy efficiently over large pressure drops
- Reduce shaft power output
- Prevent steam condensation completely
Correct Answer: Extract energy efficiently over large pressure drops
Q20. Which operational issue causes blade erosion in hydraulic turbines?
- Aerodynamic stalls
- Cavitation and particle-laden flow
- Overheating due to combustion
- Electrical short circuits
Correct Answer: Cavitation and particle-laden flow
Q21. In a steam turbine, reheat is used to:
- Increase moisture content at final stages
- Reduce turbine inlet temperature
- Improve efficiency and reduce low-stage moisture
- Cool the blades actively
Correct Answer: Improve efficiency and reduce low-stage moisture
Q22. What is the main environmental merit of using turbines in pharma plants?
- Zero noise generation
- Efficient energy conversion reduces fuel consumption and emissions
- No need for maintenance
- Total elimination of wastewater
Correct Answer: Efficient energy conversion reduces fuel consumption and emissions
Q23. Which diagnostic indicates imbalance or misalignment in turbine rotors?
- Steady low vibration at resonance
- High vibration amplitudes at operating speed
- Increased static pressure
- Reduced flow temperature only
Correct Answer: High vibration amplitudes at operating speed
Q24. What is the effect of wet steam on turbine blades?
- Improves aerodynamic lift
- Causes erosion, reduced efficiency, and vibration
- Increases electrical output directly
- Neutralizes corrosion completely
Correct Answer: Causes erosion, reduced efficiency, and vibration
Q25. Which efficiency accounts for mechanical losses like bearings and seals?
- Isentropic efficiency
- Overall or shaft efficiency
- Polytropic efficiency
- Volumetric efficiency
Correct Answer: Overall or shaft efficiency
Q26. In pharmaceutical facilities, turbines commonly supply which utilities?
- Laboratory diagnostics and testing reagents
- Power generation, steam for sterilization, and HVAC
- Direct drug formulation mixing only
- Packing label printing exclusively
Correct Answer: Power generation, steam for sterilization, and HVAC
Q27. Which type of turbine typically has the highest rotational speed for a given power?
- Large Francis turbines
- Small impulse turbines like Pelton for low stages
- Axial flow gas turbines
- Wind turbines
Correct Answer: Axial flow gas turbines
Q28. What maintenance practice minimizes fouling and efficiency loss in steam turbines?
- Frequent blade painting
- Proper steam quality control and filtration
- Using higher sulfur fuel
- Reducing condenser vacuum intentionally
Correct Answer: Proper steam quality control and filtration
Q29. Which is a demerit of using gas turbines for onsite power in pharma plants?
- Very low power-to-weight ratio
- Lower efficiency at part-load and higher NOx emissions
- Inability to start quickly
- Excessive water use
Correct Answer: Lower efficiency at part-load and higher NOx emissions
Q30. Blade profiling in turbines is designed to:
- Maximize electrical conductivity
- Optimize aerodynamic loading for efficient energy transfer
- Make blades heavier for stability
- Prevent lubrication
Correct Answer: Optimize aerodynamic loading for efficient energy transfer
Q31. Which seal type is used to prevent steam leakage along the turbine shaft?
- Radial lip seal only for liquids
- Steam labyrinth seal or brush seal
- O-ring for high-temperature steam
- Magnetic seal
Correct Answer: Steam labyrinth seal or brush seal
Q32. What role does a condenser play when coupled with a steam turbine?
- Increases steam inlet temperature
- Condenses exhaust steam to maintain low backpressure and improve efficiency
- Filters particulates from steam
- Acts as a combustion chamber
Correct Answer: Condenses exhaust steam to maintain low backpressure and improve efficiency
Q33. Which measurement is essential to evaluate turbine cavitation risk?
- Rotor surface roughness only
- NPSH (Net Positive Suction Head) or available pressure head
- Electrical insulation resistance
- Fuel viscosity
Correct Answer: NPSH (Net Positive Suction Head) or available pressure head
Q34. What is compounding in turbine design?
- Combining fuel types for combustion
- Using multiple stages to distribute energy extraction and reduce blade speed
- Mixing lubricants for better performance
- Applying coatings to blades
Correct Answer: Using multiple stages to distribute energy extraction and reduce blade speed
Q35. Which turbine component primarily transmits rotational power to generators or equipment?
- Suction nozzle
- Shaft
- Nozzle ring
- Governor spring
Correct Answer: Shaft
Q36. What is the practical benefit of back-pressure turbines in pharma plants?
- They produce higher electrical voltages
- They supply process steam at useful pressures while generating power
- They eliminate the need for condensers completely
- They require no maintenance
Correct Answer: They supply process steam at useful pressures while generating power
Q37. Which factor most directly affects turbine blade life in steam turbines?
- Color of paint used
- Steam quality and presence of contaminants
- Ambient room lighting
- Tool brand used for assembly
Correct Answer: Steam quality and presence of contaminants
Q38. What is the effect of increasing turbine inlet pressure, keeping inlet temperature constant?
- Decreases available enthalpy drop
- Generally increases power output and efficiency up to design limits
- Has no effect on performance
- Always damages blades immediately
Correct Answer: Generally increases power output and efficiency up to design limits
Q39. Which lubrication system is critical for high-speed turbine bearings?
- Grease-packed manual grease only
- Pressurized oil system with filtration and cooling
- Water spray lubrication
- Dry graphite lubrication
Correct Answer: Pressurized oil system with filtration and cooling
Q40. What is the primary safety concern when operating steam turbines in pharmaceutical settings?
- Excessive UV exposure
- High-pressure steam leaks and rotating machinery hazards
- Radiation emission from turbines
- Biological contamination from blades
Correct Answer: High-pressure steam leaks and rotating machinery hazards
Q41. Which test assesses the aerodynamic performance of turbine blades?
- pH testing
- Wind tunnel or cascade testing and computational fluid dynamics (CFD)
- Hardness testing only
- Mass spectrometry
Correct Answer: Wind tunnel or cascade testing and computational fluid dynamics (CFD)
Q42. What does the term ‘throat area’ refer to in turbine nozzles?
- The widest cross-section in a diffuser
- The smallest cross-section where flow velocity is maximized
- The area of the rotor hub
- The bearing contact surface
Correct Answer: The smallest cross-section where flow velocity is maximized
Q43. Which turbine selection parameter is especially important for variable load conditions in pharma plants?
- Fixed blade angle exclusively
- Part-load efficiency and controllability (governor capability)
- Color coding of pipes
- Ambient humidity only
Correct Answer: Part-load efficiency and controllability (governor capability)
Q44. In combined cycle plants, how are turbines used to improve overall efficiency?
- By stacking identical turbines for redundancy only
- By coupling gas turbines with steam turbines using waste heat recovery
- By replacing turbines with reciprocating engines
- By operating turbines at zero load permanently
Correct Answer: By coupling gas turbines with steam turbines using waste heat recovery
Q45. Which maintenance activity prevents bearing failure in turbines?
- Ignoring oil particle contamination
- Regular oil analysis, filtration, and temperature monitoring
- Applying paint to bearings monthly
- Running dry starts frequently
Correct Answer: Regular oil analysis, filtration, and temperature monitoring
Q46. What is the primary advantage of axial flow turbines over radial flow turbines in certain applications?
- Better performance at extremely low speeds only
- Higher flow capacity with compact axial staging and good part-load behavior
- No need for lubrication
- Lower manufacturing cost in all cases
Correct Answer: Higher flow capacity with compact axial staging and good part-load behavior
Q47. Which corrosion mechanism is commonly accelerated by wet steam?
- Stress corrosion cracking and pitting due to dissolved impurities
- Thermal oxidation only at high temperatures
- Galvanic corrosion in absence of moisture
- None; wet steam prevents corrosion
Correct Answer: Stress corrosion cracking and pitting due to dissolved impurities
Q48. Which monitoring parameter is most indicative of blade erosion or deposits forming?
- Stable thermocouple readings at inlet
- Gradual drop in turbine efficiency and altered vibration signatures
- Constant generator frequency only
- Higher condenser vacuum only
Correct Answer: Gradual drop in turbine efficiency and altered vibration signatures
Q49. Which operational strategy extends turbine life while maintaining reliability?
- Frequent emergency starts and stops without warm-up
- Proper start-up/shutdown sequences, controlled ramp rates, and scheduled inspections
- Skipping oil changes to save costs
- Operating always at maximum possible temperature
Correct Answer: Proper start-up/shutdown sequences, controlled ramp rates, and scheduled inspections
Q50. What is a primary reason for using blade coatings in steam turbines?
- To increase blade electrical conductivity
- To protect against corrosion, erosion, and improve surface finish
- To change rotor mass drastically for imbalance
- To make blades transparent for inspection
Correct Answer: To protect against corrosion, erosion, and improve surface finish
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
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