155. Sulphur in coal results in
A.Causing clinkering and slagging
B.All of the above.
C.Spontaneous combustion during coal storage
D.Facilitating ash precipitation

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156. Caking coals are those which
A.Form lumps or masses of coke
B.Burn freely
C.Show little or no fusing aciton
D.Burn completely

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157. Green coal, in order to be burnt, must be
A.Heated sufficiently
B.Burnt in excess air
C.Heated to its ignition point
D.Burnt as powder

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158. The ultimate analysis of fuel lists
A.Various chemical constituents, carbon, hydrogen, oxygen etc, plus ash as percents by volume
B.Various chemical constituents, carbon, hydrogen, oxygen, etc, plus ash as percents by weight
C.Fuel constituents as percents by volume of moisture, volatile, fixed carbon and ash
D.Fuel constituents as percents by weight of moisture, volatile, fixed carbon and ash

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159. The proximate analysis of fuel lists
A.Various chemical constituents, carbon, hydrogen, oxygen etc, plus ash as percents by volume
B.Various chemical constituents, carbon, hydrogen, oxygen, etc, plus ash as percents by weight
C.Fuel constituents as percents by volume of moisture, volatile, fixed carbon and ash
D.Fuel constituents as percents by weight of moisture, volatile, fixed carbon and ash

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160. Tertiary air is the air used to
A.Provide air around burners for obtaining optimum combustion
B.Convert CO (formed in lower zone of furnace) into CO2 at higher zone.
C.Cool the scanners
D.Supply air for ignitors

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161. The safety valve on boiler drum compared to safety valve on superheater is set at
A.Same value
B.Higher value
C.Lower value
D.Lower/higher depending on steam flOw

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