Natural water circulation, by convection in water tube boilers, with increase in pressure of boiler _________________?

A. Increases
B. Decreases
C. Remains unaffected
D. First increases and then decreases

Deaeration of feed water is carried out because it reduces ____________________?

A. Cavitation of .boiler feed pumps
B. Corrosion caused by oxygen
C. Heat transfer coefficient
D. Ph value of water

During storage, the heating value of coal __________________?

A. Increases
B. Decreases
C. Remains constant
D. May increase or decrease depending upon the method of storage

For the same diameter and thickness of tube, a water tube boiler compared to a fire tube boiler has ____________________?

A. More heating surface
B. Less heating surface
C. Equal heating surface
D. Heating surface depends on other parameters

Film boling occurs at _______________________?

A. Very low pressure
B. Atmospheric pressures
C. Medium pressures
D. Very high pressures

The size of a boiler drum in pulverised fuel fired boiler,as its size and capacity, (steam pressure and flow ratings) increase __________________?

A. Increases
B. Decreases
C. Remains unchanged
D. Increases/decreases depending on steam temperature requirements

The basic job of feed water treatment in boilers is to overcome the problem of __________________?

A. corrosion
B. scale
C. carryover
D. embrittlement

The feed check valve is used in order to ______________________?

A. Regulate flow of boiler water
B. Check level of water in boiler drum
C. Recirculate unwanted feed water
D. Allow high pressure feed water to flow to drum and not allow reverse flow to take place

In water wall furnace, the heat is transferred to the water-walls by _________________?

A. Convection
B. Radiation
C. Conduction
D. Radiation and conducton

Fire tube boilers are limited to a maximum design working pressure of ____________________?

A. 1 kg/cm
B. 6 kg/cm
C. 17 kg/cm2
D. 100 kg/cm2