Practice Test: Question Set - 10
1. Which is not the correct statement about moisture in coal?
- (A) Inherent moisture and
surface moisture are different things
- (B) In some coals moisture may be present up to
40%
- (C) Some moisture in coal helps in better
burning which is not possible with completely dry coal
- (D) It increases thermal
efficiency
2. The friction present between the steam and the nozzle surfaces reduces the heat drop by
- (A) 10 to 15%
- (B) 15 to 25%
- (C) 25 to 40%
- (D) 40 to 60%
3. The draught in locomotive boilers is produced by a
- (A) Chimney
- (B) Centrifugal
fan
- (C) Steam jet
- (D) None
of these
4. Stoichiometric quantity of air is the
- (A) Air present in
atmosphere at NTP conditions
- (B) Air required for complete combustion of
fuel with no excess air
- (C) Air required for optimum combustion so as
to have reasonable excess air
- (D) Air required to convert CO into CO₂
5. The impulse reaction turbine has its driving force
- (A) As an
impulsive force
- (B) As a
reaction force
- (C) Partly
as an impulsive force and partly as a reaction force
- (D) None of the
above
6. The average operating pressure of Benson boiler is
- (A) 100 bar
- (B) 150 bar
- (C) 200 bar
- (D) 250 bar
7. Pick up the wrong statement about critical condition of steam
- (A) Latent heat is zero
- (B) Liquid directly
becomes steam
- (C) Specific volume of
steam and liquid is same
- (D) This is the maximum
pressure limit
8. In reaction turbines, the axial thrust is due to
- (A) Pressure
drop across the rotor
- (B) Change
in axial velocity
- (C) Both (A) and
(B)
- (D) None of
these
9. The draught produced by a steam jet issuing from a nozzle placed in the chimney is called
- (A) Induced
steam jet draught
- (B) Chimney
draught
- (C) Forced
steam jet draught
- (D) None of
these
10. A packaged boiler is one in which various parts like firing equipment, fans, feed pumps and automatic controls are
- (A) Supplied by same
manufacturer loose and assembled at site
- (B) Supplied mounted on a
single base
- (C) Purchased from
several parties and packed together at site
- (D) Packaged boiler does
not exist
11. The impulse turbine rotor efficiency will have a maximum value of 0.5 cos 2α, where α is the nozzle exit flow angle, if the
- (A) Blades
are equiangular
- (B) Blade
velocity coefficient is unity
- (C) Blades
are equiangular and frictionless
- (D) Blade
solidity is 0.65
12. Lancashire boiler is used where working pressure and power required are
- (A) Low
- (B) Moderate
- (C) High
- (D) None of
these
13. Fusible plug for boilers is made of fusible metal containing tin, lead, and
- (A) Bismuth
- (B) Copper
- (C) Aluminium
- (D) Nickel
14. Which of the following statement is correct for steam turbines as compared to reciprocating steam engines?
- (A) A
steam turbine develops higher speeds
- (B) The
efficiency of steam turbine is higher
- (C) The
steam consumption is less
- (D) All of these
15. Which of the following is not a boiler mounting?
- (A) Blow off
cock
- (B) Feed
check valve
- (C) Economiser
- (D) Fusible plug
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