Steam Boilers Engines Nozzles and Turbines

151. The maximum discharge through a chimney occurs when the height of chimney is

1. infinitely long
2. around 200 meters
3. equal to the height of the hot gas column producing draught
4. outside temperature is very low
5. more than the tallest building nearby.

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152. The number of drums in Benson steam generator is

1. one
2. two
3. one steam drum and one water drum
4. no drum
5. none of the above.

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153. The number of flue tubes in Lancashire boiler is

1. zero
2. one
3. two
4. four
5. many.

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154. The overall efficiency of thermal power plant is

1. boiler efficiency, turhine efficiecny, generator efficiency
2. all the three above plus gas cycle efficiency
3. carnot cycle efficiency
4. regenerative cycle efficiency
5. rankine cycle efficiency.

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155. The pressure at which latent heat of vaporisation of water is zero, is

1. below atmospheric pressure
2. 1 kg/cm2
3. 100 kg/cm2
4. 170 kg/cm2
5. 225.6 kg/cm2.

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156. The pressure of reheat steam after passing through reheater compared to inlet condition is

1. more
2. less
3. equal
4. may be more or less depending on capacity of reheater
5. none of the above.

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157. The proximate 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.

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158. The radius of a dished head is taken approximately as

1. one-fourth
2. half
3. one
4. two
5. three.

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159. The ratio of heat utilised to produce steam and the heat liberated in furnace is known as

1. boiler effectiveness
2. boiler evaporative capacity
3. factor of evaporation
4. equivalent evaporation
5. boiler efficiency.

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160. The relative heat absorption for successively added equal areas of boiler convection heating surfaces

1. increases
2. decreases
3. remains unaffected
4. first increases and then decreases
5. first decreases and then increases.

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