Mechanical Engineering Mcqs
With increase in load, convection superheater has_______________________?

A. Drooping characteristic
B. Linear characterisstic
C. Rising characteristic
D. Flat characteristic

The temperature of flue gases at air heater outlet should be__________________?

A. 100°c
B. Above dew-point temperature of flue gases
C. Below dew-point temperature of flue gases
D. Less than wet bulb temperature of flue gases

In a recuperative air preheater, the heat is transferred____________________?

A. From a metal wall from one medium to another
B. From heating an itermediate material and then heating the air from this material
C. By direct mixing ,
D. Heat is transferred by bleeding some gases from furnace

The function of injector used in small capacity boilers is to____________________?

A. Create vacuum
B. Inject chemical solution in feed pump
C. Pump water, similar to boiler feed pump
D. Add make up water in the system

In designing air preheater, the important design consideration is that_________________?

A. Approach temperature should be as low as possible
B. Handling and maintenance should be easier
C. Heat transfer area should be optimum
D. Stack gases should not be cooled to the dew point

The height of chimney in a power plant is governed by__________________?

A. The draft to be created
B. Limitation of construction facilities
C. Control of pollution
D. Quantity of flue gases to be handled

In locomotives, the draught is produced by_________________?

A. Chimney
B. Induced draft fan
C. Both combined a. and b.
D. Steam jet draught

Vacuum for reciprocating steam engines compared to steam turbines is__________________?

A. More
B. Equal
C. Less
D. Could be more or less depending on the size of plant

The maximum discharge through a chimney occurs when the height of chimney is_____________________?

A. Infinitely long
B. Around 200 meters
C. Equal to the height of the hot gas column producing draught
D. Outside temperature is very low