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101.

The silica in Portland cement should be

A.	10 to 20%	B.	20 to 25%
C.	25 to 40%	D.	40 to 60%

102.

The dry process of mixing is usually employed in the manufacture of Portland cement when the raw material is

A.	blast furnace slag	B.	chalk
C.	clay	D.	all of these

103.

The clinker is formed at a temperature of

A.	500?C	B.	1000?C
C.	1200?C	D.	1500?C

104.

The amount of gypsum, usually, added in the manufacture of cement is

A.	0.1 to 0.5%	B.	0.5 to 1%
C.	1 to 3%	D.	3 to 5%

105.

Gypsum is added in the manufacture of Portland cement

A.	while mixing the raw materials	B.	during burning in the rotary kiln
C.	at the beginning of grinding the clinker	D.	at the end of grinding the clinker into powder

106.

Gypsum is added in the manufacture of Portland cement in order to

A.	shorten the setting time of cement	B.	lengthen the setting time of cement
C.	decrease the burning temperature	D.	decrease the grinding time

107.

The cementing property in cement is mainly due to

A.	lime	B.	silica
C.	iron oxide	D.	alumina

108.

The setting and hardening of cement paste is mainly due to the hydration and hydrolysis of

A.	tri-calcium silicate	B.	di-calcium silicate
C.	tri-calcium aluminate	D.	all of these

109.

The greater the percentage of tri-calcium silicate in the cement, the better will be the cement.

Correct

Incorrect

110.

The compound responsible for the initial setting of cement, is

A.	tri-calcium aluminate	B.	tetra-calcium alumino ferrite
C.	both (a) and (b)	D.	none of these