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141.

If ash content of coke used in cupola is high then

A.	melting rate will be low	B.	more of flux will be required
C.	castings produced will have blow holes	D.	carbon content of castings will be low

142.

Coke used in cupola is in the form of

A.	coal dust	B.	pulverized coal
C.	lumps	D.	any of the above

143.

Thermal efficiency of cupola is in the range

A.	80 to 90 percent	B.	60 to 75 percent
C.	50 to 65 percent	D.	30 to 50 percent

144.

The disadvantage of hot blast cupola is

A.	low coke consumption	B.	reduced silicon loss
C.	reduced output silicon loss	D.	all of the above

145.

The advantage of oxygen enriched cupola is

A.	higher temperature of molten iron	B.	high efficiency of cupola
C.	reduced heat loss in waste gases	D.	all of the above

146.

During the passage of molten metal through the coke, the carbon percentage of the molten metal increases. The absorption of carbon depends on

A.	size of the coke	B.	temperature
C.	time allowed for molten metal to remain in the cupola	D.	all of the above

147.

As a result of melting of cast iron in cupola, which of the following constituent undergoes least change in its percentage?

A.	Silicon	B.	Sulphur
C.	Manganese	D.	Phosphorous

148.

As a result of melting in cupola, the percentage of all of the following constituents decreases EXCEPT:

A.	Silicon	B.	Sulphur
C.	Carbon	D.	Phosphorous

149.

Which inoculant is used to produced ductile iron?

A.	Magnesium	B.	Carbon
C.	Graphite	D.	Fluorides

150.

Contraction of metal starts at the end of

A.	liquid stage	B.	mushy stage
C.	plastic stage	D.	solid stage