Steam Boilers Engines Nozzles and Turbines

171. The three "Ts" for good combustion are

1. temperature, time, and turbulance
2. total air, true fuel, and turbulance
3. thorough mixing, total air, and temperature
4. total air, time, and temperature
5. none of the above.

View answer

172. The ultimate analysis of fuel lists

1. various chemical constituents, carbon, hydrogen, oxygen etc, plus ash as per-cents by volume
2. various chemical constituents, carbon, hydrogen, oxygen, etc, plus ash as per-cents by weight
3. fuel constituents as percents by volume of moisture, volatile, fixed carbon and ash
4. fuel constituents as percents by weight of moisture, volatile, fixed carbon and ash
5. moisture and ash free heating value.

View answer

173. The water tubes in a babcock and wilcox boiler are

1. horizontal
2. vertical
3. inclined
4. horizontal and inclined
5. vertical and inclined.

View answer

174. Thermal efficiency of a thermal power plant is of the order of

1. 15%
2. 20%
3. 30%
4. 45%
5. 60%.

View answer

175. Thermal efficiency of well maintained boiler will be of the order

1. 20%
2. 40%
3. 50%
4. 75%
5. 90%.

View answer

176. Ultimate analysis of fuel is determination of percentage of

1. carbon, hydrogen, nitrogen, sulphur, moisture
2. fixed carbon, ash, volatile matter, moisture
3. higher calorific value
4. lower calorific value
5. best analysis.

View answer

177. Vacuum for reciprocating steam engines compared to steam turbines is

1. more
2. equal
3. less
4. could be more or less depending on the size of plant
5. none of the above.

View answer

178. Water and sediment in fuel oil can be removed by

1. heating the oil in the settling tanks
2. cooling the oil in the settling tanks
3. burning the oil
4. suspension
5. filtering.

View answer

179. Water at pressure of 4 kg/cm2 and 160°C temperature when exposed to atmosphere will

1. boil
2. flash i.e. get converted into steam
3. remain as it was
4. cool down
5. none of the above.

View answer

180. Water boils when its vapour pressure

1. equals that of the surroundings
2. equals 760 mm of mercury
3. equals to atmospheric pressure
4. equals the pressure of water in the container
5. boiling has ^nothing to do with vapour pressure.

View answer