1121. What salts of calcium and magnesium cause temporary hardness of boiler feed water ?

A. Chlorides
B. Bicarbonates *
C. Nitrates
D. Sulphites

1122. Foaming in a boiler feed water is due to the presence of :

A. Oil *
B. Calcium Carbonate
C. Manganeses
D. Sodium Chloride

1123. Scale is formed on the boiler surface when the boiler feed water contains :

A. Dissolved gases
B. Oils and suspended solids
C. Calcium and magnesium salts *
D. Insoluble compounds

1124. Deaeration of feed water is done to reduce :

A. Necessity of priming in feed pumps
B. Mass of water to be handled
C. Corrosion caused by dissolved oxygen *
D. Amount of heat required to convert water into steam

1125. Oxygen can be removed from the boiler feed water by the addition of :

A. Alum
B. Calcium carbonate
C. Sodium Sulphite *
D. Cuprous chloride

1126. Which of the following characteristics decides that the lancashire boiler is a fire tube boiler ?

A. Horizontal erection
B. Coal Firing
C. Use of two flue tubes through which flow the hot gases and water is kept around the tubes*
D. All around brick work setting for the circulation of hot gases

1127. Lancashire boiler is a _________ boiler:

A. Single pass
B. Two pass
C. Three pass*
D. Four pass

1128. The diameter of the cylindrical shell of lancashire boiler is about :

A. 0.75-1.25 m
B. 1.25-2M
C. 1.75-2.75 m *
D. 2-3.5 m

1129. In a Lancashire boiler, the diameter of internal flue tubes and the shell diameter conform to the ratio :

A. 1:2
B. 2:5 *
C. 1:3
D. 1:5

1130. A Babcock-wilcox boiler is classified as a water tube boiler because :

A. It has a large bank of tubesand a steam drum
B. Water passes through the tubesand hot gases flow around the tubes *
C. Water evaporates in the drums
D. Superheater is mounted directly above the bank of tubes