Practice Test: Question Set - 24
1. Green coal, in order to be burnt, must be
- (A) Heated sufficiently
- (B) Burnt in excess air
- (C) Heated to its ignition point
- (D) Burnt as powder
2. A safety valve usually employed with stationary boilers is
- (A) Lever safety valve
- (B) Dead weight safety valve
- (C) High steam and low water safety valve
- (D) All of these
3. The relative heat absorption for successively added equal areas of boiler convection heating surfaces
- (A) Increases
- (B) Decreases
- (C) Remain unaffected
- (D) First increases and then decreases
4. The pressure of steam in the engine cylinder at the beginning of the stroke is ________ the boiler pressure.
- (A) Equal to
- (B) Less than
- (C) Higher than
- (D) None of these
5. Adiabatic process is
- (A) Essentially an isentropic process
- (B) Non-heat transfer process
- (C) Reversible process
- (D) Constant temperature process
6. Lancashire boiler is
- (A) Stationary fire tube boiler
- (B) Internally fired boiler
- (C) Horizontal boiler
- (D) All of these
7. Cochran boiler is a
- (A) Horizontal fire tube boiler
- (B) Horizontal water tube boiler
- (C) Vertical water tube boiler
- (D) Vertical fire tube boiler
8. Blow off cock in a boiler is used to
- (A) Control the flow of steam from the boiler to the main pipe and to shut off the steam completely when required
- (B) Empty the boiler when required and to discharge the mud, scale or sediments which are accumulated at the bottom of the boiler
- (C) Put off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit
- (D) Increase the temperature of saturated steam without raising its pressure
9. The diameter of internal flue tubes in a Lancashire boiler compared to its shell is
- (A) One-half
- (B) One-third
- (C) Two-fourth
- (D) Two-fifth
10. When the circulation of water, in a boiler, is by convection currents which are set up during the heating of water, then the boiler is known as
- (A) Internally fired boiler
- (B) Externally fired boiler
- (C) Natural circulation boiler
- (D) Forced circulation boiler
11. Thermal efficiency of a thermal power plant is of the order of
- (A) 15 %
- (B) 20 %
- (C) 30 %
- (D) 45 %
12. The high steam and low water safety valve is not used in
- (A) Cochran boiler
- (B) Cornish boiler
- (C) Lancashire boiler
- (D) Locomotive boiler
13. Expanding steam to a very low pressure (high vacuum) in steam engines is
- (A) Desirable
- (B) Economical
- (C) Essential
- (D) Uneconomical
14. The cylinder dimensions of a compound engine may be designed on the basis of
- (A) Equal power developed in each cylinder for uniform turning moment
- (B) Equal initial piston loads on all pistons for obtaining same size of piston rod, connecting rod etc. for all cylinders
- (C) Equal temperature drop in each cylinder for economy of steam
- (D) All of the above
15. One kilowatt-hour energy is equivalent to
- (A) 1000 J
- (B) 360 kJ
- (C) 3600 kJ
- (D) 3600 kW/sec