Practice Test: Question Set - 20
1. Mechanical equivalent of heat for 1 kcal or Joule's equivalent is equal to
- (A) 421 kg.m
- (B) 421 kg.m
- (C) 539 kg.m
- (D) 102 kg.m
2. The effect of super-saturation is that the
- (A) Mass
of the steam discharged increases
- (B) Entropy
and specific volume of the steam increases
- (C) Exit
velocity of steam reduces
- (D) All
of these
3. The diameter of superheated tubes in a locomotive boiler is
- (A) 13
mm
- (B) 31
mm
- (C) 130
mm
- (D) 230
mm
4. The change in internal energy in steam engines equals to
- (A) Work done during the
Rankine cycle
- (B) Work done during
compression
- (C) Work done during
adiabatic expansion
- (D) Change in enthalpy
5. The pressure velocity compounded impulse turbine allows a bigger pressure drop and hence __________ numbers of stages are required.
- (A) More
- (B) Less
- (C) Equal
- (D) None
of these
6. In fire tube boilers
- (A) Water
passes through the tubes which are surrounded by flames and hot gases
- (B) The
flames and hot gases pass through the tubes which are surrounded by water
- (C) Forced
circulation takes place
- (D) None
of these
7. The shell diameter and length of locomotive boiler are
- (A) 1.5 m, 4 m
- (B) 1.5 m, 6 m
- (C) 1 m, 4 m
- (D) 2 m, 4 m
8. The ratio of the workdone on the blades to the energy supplied to the blades, is called
- (A) Blading
efficiency
- (B) Nozzle
efficiency
- (C) Gross
or stage efficiency
- (D) Mechanical
efficiency
9. The numbers of fire tubes in a Cochran boiler are
- (A) 75
- (B) 115
- (C) 165
- (D) 225
10. In forced 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
11. The critical pressure ratio for initially dry saturated steam is
- (A) 0.546
- (B) 0.577
- (C) 0.582
- (D) 0.601
12. In cross compounding, the cylinders are arranged
- (A) Side
by side and each cylinder has common piston, connecting rod and crank
- (B) Side
by side and each cylinder has separate piston, connecting rod and crank
- (C) At
90° and each cylinder has common piston, connecting rod and crank
- (D) At
90° and each cylinder has separate piston, connecting rod and crank
13. Vacuum for reciprocating steam engines compared to steam turbines is
- (A) More
- (B) Equal
- (C) Less
- (D) Could be more or less
depending on the size of plant
14. In a nozzle, the effect of super-saturation is to
- (A) Decrease
dryness fraction of steam
- (B) Decrease
specific volume of steam
- (C) Increase
the entropy
- (D) Increase
the heat drop
15. The cylindrical shell of a Lancashire boiler has diameter from
- (A) 1 to 2 m
- (B) 1.25 to 2.25
m
- (C) 1.5 to 2.5 m
- (D) 1.75 to 2.75
m