Multiple Choice Questions on Steam Nozzles and Boilers - Set 12 - ObjectiveBooks

# Practice Test: Question Set - 12

1. On Millier chart, the constant pressure lines
(A) Diverge from left to right
(B) Diverge from right to left
(C) Are equally spaced throughout
(D) First rise up and then fall

2. The reheat factor depends upon
(A) Initial pressure and superheat
(B) Exit pressure
(C) Turbine stage efficiency
(D) All of these

3. In a boiler, feed water supplied per hour is 205 kg while coal fired per hour is 23 kg. The net enthalpy rise per kg of water is 145 kJ. If the calorific valve of the coal is 2050 kJ/kg, then the boiler efficiency will be
(A) 56 %
(B) 63 %
(C) 74 %
(D) 78 %

4. The state of vapor under saturation condition is described by
(A) Pressure alone
(B) Temperature alone
(C) Pressure and temperature
(D) Pressure and dryness fraction

5. The diagram efficiency is the ratio of
(A) Workdone on the blades to the energy supplied to the blades
(B) Workdone on the blades per kg of steam to the total energy supplied per stage per kg of steam
(C) Energy supplied to the blades per kg of steam to the total energy supplied per stage per kg of steam
(D) None of the above

6. Locomotive boiler is a
(A) Single tube, horizontal, internally fired and stationary boiler
(B) Single tube, vertical, externally fired and stationary boiler
(C) Multi-tubular, horizontal, internally fired and mobile boiler
(D) Multi-tubular, horizontal, externally fired and stationary boiler

7. 100% efficiency of a thermal cycle cannot be achieved because of
(A) Frictional losses
(B) It is not possible to achieve 0°K temperature
(C) Leakage
(D) Non availability of ideal substance

8. In a velocity compounded impulse turbine, when steam flows through the second row of moving blades,
(A) Velocity increases
(B) Velocity decreases
(C) Velocity remains constant
(D) Pressure remains constant

9. Cut-off governing as compared to throttle governing is
(A) Less efficient and less economical
(B) Less efficient and more economical
(C) More efficient and less economical
(D) More efficient and more economical

10. Which of the following coals has the highest calorific value?
(A) Anthracite coal
(B) Bituminous coal
(C) Lignite
(D) Peat

11. In a Parson's turbine stage, blade velocity is 320 m/s at the mean radius and rotor blade exit angle is 30°. For minimum kinetic energy of the steam leaving the stage, the steam velocity at the exit of the rotor will be
(A) 160/3 m/s
(B) 320/3 m/s
(C) 640/3 m/s
(D) 640 m/s

12. The main object of a boiler trial is
(A) To determine the generating capacity of the boiler
(B) To determine the thermal efficiency of the boiler when working at a definite pressure
(C) To prepare heat balance sheet for the boiler
(D) All of the above

13. Hard coke is used in
(A) Cement industry
(B) Thermal power plant
(C) Blast furnace
(D) Domestic use

14. The velocity of whirl at outlet for an axial discharge turbine is
(A) Minimum
(B) Maximum
(C) Zero
(D) None of these

15. The ratio of the volume at cut-off to the swept volume is called
(A) Cut-off ratio
(B) Expansion ratio
(C) Clearance ratio
(D) None of these

Show and hide multiple DIV using JavaScript View All Answers

Blogger Comment