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This set of Thermal Engineering 1 Multiple Choice Questions & Answers (MCQs) focuses on Boilers, Mountings and Accessories
Q1 | The diameter of fire tubes in Cochran boiler is of the order of
- 2 cm
- 6 Cm
- 8 cm
- 12 cm
Q2 | In a recuperative air preheater, the heat is transferred
- from a metal wall from one medium to another
- from heating an itermediate material and then heating the air from this material
- by direct mixing ,
- heat is tr
Q3 | The function of injector used in small capacity boilers is to
- create vacuum
- inject chemical solution in feed pump
- pump water, similar to boiler feed pump
- add make up water in the system
Q4 | The maximum discharge through a chimney occurs when the height of chimney is
- infinitely long
- around 200 meters
- equal to the height of the hot gas column producing draught
- outside temperature is very low
Q5 | The economiser is used in boilers to
- increase thermal efficiency of boiler
- economise on fuel
- extract heat from the exhaust flue gases
- increase flue gas temperature
Q6 | An economiser in a boiler
- increases steam pressure
- increases steam flow
- decreases fuel consumption
- decreases steam pressure
Q7 | The safety valve on boiler drum compared to safety valve on superheater is set at
- same value
- higher value
- lower value
- lower/higher depending on steam flow
Q8 | The capacity of induced draft fan compared to forced draft fan in a boiler is
- same
- more
- less
- less or more depending on size of boiler
Q9 | Evaporative capacity of boiler is expressed as
- kg of steam produced
- steam pressure produced
- kg of fuel fired
- kg of steam produced per kg of fuel fired
Q10 | The condition of steam in boiler drum is always
- dry
- wet
- saturated
- superheated.
Q11 | The balanced draft furnace is one using
- induced draft fan and chimney
- induced draft fan and forced draft fan
- forced draft fan and chimney
- any one of the above
Q12 | Fire tube boilers are limited to a maximum design working pressure of
- 1 kg/cm
- 6 kg/cm
- 17 kg/cm2
- 100 kg/cm2
Q13 | For the same diameter and thickness of tube, a water tube boiler compared to a fire tube boiler has
- more heating surface
- less heating surface
- equal heating surface
- heating surface depends on other parameters
Q14 | The feed check valve is used in order to
- regulate flow of boiler water
- check level of water in boiler drum
- recirculate unwanted feed water
- allow high pressure feed water to flow to drum and not allow reverse flow to take place
Q15 | Equivalent evaporation is the amount of water evaporated in a boiler from and at
- 0°C
- 100°C
- saturation temperature at given pressure
- room temperature
Q16 | The equivalent evaporation of a boiler is a measure to compare
- the given boiler with the model
- the two different boilers of the same make
- two different makes of boilers operat¬ing under the same operating conditions
- any type of boilers operating under any conditions.
Q17 | Steam nozzle converts
- heat energy of steam into pressure energy
- heat energy of steam into kinetic energy
- pressure energy of steam into heat energy
- pressure energy of steam into potential energy
Q18 | A nozzle is designed for
- maximum pressure at the outlet
- maximum discharge
- maximum pressure and maximum discharge
- maximum kinetic energy at the outlet
Q19 | Ideal expansion of steam through a nozzle is considered
- isothermal
- adiabatic
- polytropic
- none of the above
Q20 | Presence of frictional effect during flow through the nozzle
- reduces the exit velocity
- increases the exit velocity
- has no effect on exit velocity
- none of the above
Q21 | Frictional losses in the nozzle
- reduces the heat drop
- increases the heat drop
- has no effect on heat drop
- none of the above
Q22 | While steam expands in turbines, theoretically the entropy
- remains constant
- increases
- decreases
- behaves unpredictably
Q23 | Nozzle efficiency is defined as
- ratio of isentropic heat drop to useful heat drop
- ratio of useful heat drop to isentropic heat drop
- product of useful heat drop and isentropic heat drop
- none of the above
Q24 | When a nozzle operates with maximum mass flow, it is said to be
- under expanding flow
- over expanding flow
- choked flow
- none of the above
Q25 | For supersaturated flow in the nozzle, the discharge
- increases
- decreases
- remains constant
- none of the above