Steam Turbines MCQ Practice Tests - Set 07

Practice Test: Question Set - 07

1. Efficiency of Rankine cycle can be increased by
    (A) Decreasing initial steam pressure and temperature
    (B) Increasing exhaust pressure
    (C) Decreasing exhausts pressure
    (D) Increasing the expansion ratio

2. In an impulse turbine
    (A) The steam is expanded in nozzles only and there is a pressure drop and heat drop
    (B) The steam is expanded both in fixed and moving blades continuously
    (C) The steam is expanded in moving blades only
    (D) The pressure and temperature of steam remains constant

3. For the same diameter and thickness of tube, a water tube boiler has ________ heating surface as compared to fire tube boiler.
    (A) More
    (B) Less
    (C) Equal
    (D) None of these

4. Which of the following is a water tube boiler?
    (A) Locomotive boiler
    (B) Cochran boiler
    (C) Cornish boiler
    (D) Babcock and Wilcox boiler

5. In a reaction turbine
    (A) The steam is allowed to expand in the nozzle, where it gives a high velocity before it enters the moving blades
    (B) The expansion of steam takes place partly in the fixed blades and partly in the moving blades
    (C) The steam is expanded from a high pressure to a condenser pressure in one or more nozzles
    (D) The pressure and temperature of steam remains constant

6. The selection of type and size of a steam boiler depends upon
    (A) The power required and working pressure
    (B) The geographical position of the power house
    (C) The fuel and water available
    (D) All of the above

7. In natural circulation type boiler,
    (A) Heating takes place at bottom and the water supplied at bottom gets converted into the mixture of steam bubbles and hot water which rise to drum
    (B) Water is supplied in drum and through down comers located in atmospheric condition it passes to the water wall and rises to drum in the form of mixture of water and steam
    (C) Feed pump is employed to supplement natural circulation in water wall type furnace
    (D) Water is converted into steam in one. Pass without any recirculation

8. The maximum efficiency of a De-Laval turbine is (where α = Nozzle angle)
    (A) sin²α
    (B) cos²α
    (C) tan²α
    (D) cot²α

9. A _________ in a boiler is used to put off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit.
    (A) Blow off cock
    (B) Fusible plug
    (C) Stop valve
    (D) Safety valve

10. The ratio of heat utilized to produce steam and the heat liberated in furnace is known as
    (A) Boiler effectiveness
    (B) Boiler evaporative capacity
    (C) Factor of evaporation
    (D) Boiler efficiency

11. The blade friction in the impulse turbine reduces the velocity of steam by __________ while it passes over the blades.
    (A) 10 to 15%
    (B) 15 to 20%
    (C) 20 to 30%
    (D) 30 to 40%

12. For the same length of stroke and speed of crankshaft, the piston speed for a double acting steam engine is _________ the piston speed of single acting steam engine.
    (A) Equal to
    (B) Twice
    (C) Three times
    (D) Four times

13. The height of chimney in a power plant is governed by
    (A) The draft to be created
    (B) Limitation of construction facilities
    (C) Control of pollution
    (D) Quantity of flue gases to be handled

14. In impulse turbines, when friction is neglected, the relative velocity of steam at outlet tip of the blade is _________ the relative velocity of steam at inlet tip of the blade.
    (A) Equal to
    (B) Less than
    (C) Greater than
    (D) None of these

15. The fittings mounted on the boiler for its proper and safe functioning is a
    (A) Water level indicator
    (B) Pressure gauge
    (C) Safety valve
    (D) All of these

Show and hide multiple DIV using JavaScript View All Answers

Share on Google Plus

    FB Comments


Post a Comment