Proper proportioning of concrete, ensures

desired strength and workability

water tightness of the structure

The maximum amount of dust which may be permitted in aggregates is

5% of the total aggregates for low workability with a coarse grading

10% of the total aggregates for low workability with a fine grading

20% of the total aggregates for a mix having high workability with fine grading

Construction joints are provided

where the member is supported by other member

at 18 m apart in huge structures

Hydration of cement is due to chemical action of water with

Tricalcium silicate and dicalcium silicate

Dicalcium silicate and tricalcium aluminate

Tricalcium aluminate and tricalcium alumino ferrite

To ensure constant moisture content in aggregates

area of each aggregate pile should be large

height of each aggregate pile should not exceed 1.50 m

aggregate pile should be left for 24 hours before aggregates are used

The risk of segregation is more for

larger proportion of maximum size aggregate

The aggregate impact value of the aggregate used in

building concrete is less than 45

road pavement concrete is less than 30

runway concrete is less than 30

reduces the shrinkage of concrete

preserves the properties of concrete

prevents the loss of water by evaporation

The bulk density of aggregates does not depend upon :

size and shape of the container

During conversion of ammonium carbamate into urea, presence of large excess of water

reduces the evaporator load by diluting the urea solution.

adversely affects the yield of urea.

reduces the evaporator load by diluting the urea solution.

does not affect the yield of urea.

Ammonium nitrate (a fertiliser) is coated with limestone powder to

add extra nutrient as fertiliser.

Calcium ammonium nitrate (CAN) is

not a fertiliser ; it is an explosive

Fertiliser plants get their N₂ requirements

by dissociating oxides of nitrogen.

by fractionation of liquified air.

by dissociating oxides of nitrogen.

5-10-5 fertilisers mean that they contain

only 5 to 10% active fertiliser constituents.

5, 10, 5% respectively of N₂, P₂O₅ and K₂O.

only 5 to 10% active fertiliser constituents.

5 to 10% filler & carrier of soil conditioners.

Electric process as compared to wet process (for the manufacture of phosphoric acid)

produces a valuable by-product called gypsum.

can use only high grade phosphate rock.

produces a valuable by-product called gypsum.

Excessive use of chemical fertilisers causes shrivelling of the roots and wilting of the plant, because the

osmotic pressure of the soil water becomes less than that of the plant sap.

osmotic pressure of the soil water becomes higher than that of the plant sap.

2171 + Mcqs in Technology Page 38 McqOptions

1851.	The ratio of the length to breadth of a wooden float, is
A.	4.5
B.	5.5
C.	6.5
D.	7.5
Answer» E.

Discussion

1852.	The following proportion of the ingredients of concrete mix, is not in conformation to arbitrary method of proportioning
A.	1 : 1 : 2
B.	1 : 2 : 4
C.	1 : 3 : 6
D.	1 : 4 : 10
Answer» E.

Discussion

1853.	Proper proportioning of concrete, ensures
A.	desired strength and workability
B.	desired durability
C.	water tightness of the structure
D.	all the above.
Answer» E.

Discussion

1854.	The maximum amount of dust which may be permitted in aggregates is
A.	5% of the total aggregates for low workability with a coarse grading
B.	10% of the total aggregates for low workability with a fine grading
C.	20% of the total aggregates for a mix having high workability with fine grading
D.	all the above.
Answer» E.

Discussion

1855.	An aggregate is said to be flaky if its least dimension is less than
A.	1/5th of mean dimension
B.	2/5th of mean dimension
C.	3/5th of mean dimension
D.	4/5th of mean dimension
Answer» D. 4/5th of mean dimension

Discussion

1856.	Construction joints are provided
A.	where B.M. and S.F. are small
B.	where the member is supported by other member
C.	at 18 m apart in huge structures
D.	all the above.
Answer» E.

Discussion

1857.	The high strength of rapid hardening cement at early stage, is due to its
A.	finer grinding
B.	burning at high temperature
C.	increased lime cement
D.	higher content of tricalcium.
Answer» D. higher content of tricalcium.

Discussion

1858.	Slump test is done for
A.	clay
B.	sand
C.	lime
D.	concrete.
Answer» E.

Discussion

1859.	For the construction of cement concrete floor, the maximum permissible size of aggregate, is
A.	4 mm
B.	6 mm
C.	8 mm
D.	10 mm
Answer» E.

Discussion

1860.	Curing a concrete for long period ensures better
A.	volume stability
B.	strength
C.	water resistance
D.	all the above.
Answer» E.

Discussion

1861.	If 20 kg of coarse aggregate is sieved through 80 mm, 40 mm, 20 mm, 10 mm, 4.75 mm, 2.36 mm, 1.18 mm, 600 micron, 300 micron and 150 micron standard sieves and the weights retained are 0 kg, 2 kg, 8 kg, 6 kg, 4 kg respectively, the fineness modulus of the aggregate, is
A.	7.30
B.	7.35
C.	7.40
D.	7.45
Answer» D. 7.45

Discussion

1862.	The commonly used material in the manufacture of cement is
A.	sand stone
B.	slate
C.	lime stone
D.	graphite.
Answer» D. graphite.

Discussion

1863.	Workability improved by adding
A.	air-entraining agent
B.	foaming agent
C.	oily-agent
D.	all the above.
Answer» E.

Discussion

1864.	Hydration of cement is due to chemical action of water with
A.	Tricalcium silicate and dicalcium silicate
B.	Dicalcium silicate and tricalcium aluminate
C.	Tricalcium aluminate and tricalcium alumino ferrite
D.	All the above.
Answer» E.

Discussion

1865.	The standard sand now a days used in India, is obtained from
A.	Jaipur (Rajasthan)
B.	Jullundur (Punjab)
C.	Hyderabad (Andhra Pradesh)
D.	Ennore (Madras)
Answer» E.

Discussion

1866.	To ensure constant moisture content in aggregates
A.	area of each aggregate pile should be large
B.	height of each aggregate pile should not exceed 1.50 m
C.	aggregate pile should be left for 24 hours before aggregates are used
D.	all the above.
Answer» E.

Discussion

1867.	Permissible compressive strength of M 300 concrete grade is
A.	100 kg/cm²
B.	150 kg/cm²
C.	200 kg/cm²
D.	300 kg/cm²
Answer» E.

Discussion

1868.	To obtain cement dry powder, lime stones and shales or their slurry, is burnt in a rotary kiln at a temperature between
A.	1100° and 1200°C
B.	1200° and 1300°C
C.	1300° and 1400°C
D.	1400° and 1500°C
Answer» E.

Discussion

1869.	After casting, an ordinary cement concrete on drying
A.	expands
B.	mix
C.	shrinks
D.	none of these.
Answer» D. none of these.

Discussion

1870.	The risk of segregation is more for
A.	wetter mix
B.	larger proportion of maximum size aggregate
C.	coarser grading
D.	all the above.
Answer» E.

Discussion

1871.	According to I.S. : 456, the number of grades of concrete mixes, is
A.	3
B.	4
C.	5
D.	7
Answer» E.

Discussion

1872.	The mixture of different ingredients of cement, is burnt at
A.	1000°C
B.	1200°C
C.	1400°C
D.	1600°C
Answer» D. 1600°C

Discussion

1873.	For ensuring quality of concrete, use
A.	single sized aggegates
B.	two sized aggregate
C.	graded aggregates
D.	coarse aggregates.
Answer» D. coarse aggregates.

Discussion

1874.	The maximum percentage of chemical ingredient of cement is that of
A.	magnesium oxide
B.	iron oxide
C.	aluminium
D.	lime
Answer» E.

Discussion

1875.	The aggregate impact value of the aggregate used in
A.	building concrete is less than 45
B.	road pavement concrete is less than 30
C.	runway concrete is less than 30
D.	all the above.
Answer» E.

Discussion

1876.	Placing of concrete should preferably be done at a temperature of
A.	0°C
B.	10°C
C.	20°C
D.	27 ± 2°C
Answer» E.

Discussion

1877.	Specified compressive strengh of concrete is obtained from cube tests at the end of
A.	3 days
B.	7 days
C.	14 days
D.	28 days.
Answer» E.

Discussion

1878.	While compacting the concrete by a mechanical vibrator, the slump should not exceed
A.	2.5 cm
B.	5.0 cm
C.	7.5 cm
D.	10 cm
Answer» C. 7.5 cm

Discussion

1879.	Curing
A.	reduces the shrinkage of concrete
B.	preserves the properties of concrete
C.	prevents the loss of water by evaporation
D.	all of the above.
Answer» E.

Discussion

1880.	The bulk density of aggregates does not depend upon :
A.	size and shape of aggregates
B.	specific gravity of aggregates
C.	grading of aggregates
D.	size and shape of the container
Answer» E.

Discussion

1881.	Heating of orthophosphoric acid to 250°C produces
A.	metaphosphoric acid
B.	pyrophosphoric acid
C.	no change in it
D.	none of these
Answer» C. no change in it

Discussion

1882.	During conversion of ammonium carbamate into urea, presence of large excess of water
A.	increases the yield of urea.
B.	adversely affects the yield of urea.
C.	reduces the evaporator load by diluting the urea solution.
D.	does not affect the yield of urea.
Answer» C. reduces the evaporator load by diluting the urea solution.

Discussion

1883.	H₃PO₄ is the chemical formula of __________ phosphoric acid.
A.	pyro
B.	ortho
C.	meta
D.	none of these
Answer» C. meta

Discussion

1884.	Action of phosphoric acid on rock phosphate produces
A.	superphosphate
B.	triple superphosphate
C.	nitrophosphate
D.	diammonium phosphate
Answer» C. nitrophosphate

Discussion

1885.	Ammonium nitrate (a fertiliser) is coated with limestone powder to
A.	increase its nitrogen content.
B.	cut down its production cost.
C.	avoid the risk of explosion.
D.	add extra nutrient as fertiliser.
Answer» D. add extra nutrient as fertiliser.

Discussion

1886.	The concentration (weight %) of nitric acid produced by the oxidation of ammonia and absorption of nitrogen oxides with water is about __________ percent.
A.	60
B.	30
C.	95
D.	100
Answer» B. 30

Discussion

1887.	CO₂ present in reformed gas (obtained by steam reforming of naphtha) is removed by absorbing in
A.	mono-ethanolamine (MEA)
B.	slaked lime
C.	ammoniacal liquor
D.	Methyl-Ethyl Ketone (MEK)
Answer» B. slaked lime

Discussion

1888.	Calcium ammonium nitrate (CAN) is
A.	a mixed fertiliser
B.	a straight fertiliser
C.	a complex fertiliser
D.	not a fertiliser ; it is an explosive
Answer» D. not a fertiliser ; it is an explosive

Discussion

1889.	Urea is represented as
A.	NH₂.CO.NH₂
B.	NH₃CO.CH₃
C.	NH.CO₂.NH
D.	NH₃.CO₂.NH₃
Answer» B. NH₃CO.CH₃

Discussion

1890.	Fertiliser plants get their N₂ requirements
A.	by fractionation of liquified air.
B.	by dissociating oxides of nitrogen.
C.	from coal gas (coke oven gas).
D.	from producer gas.
Answer» B. by dissociating oxides of nitrogen.

Discussion

1891.	Catalytic ammonia synthesis reaction as in Haber's process is
A.	endothermic
B.	exothermic
C.	irreversible
D.	none of these
Answer» C. irreversible

Discussion

1892.	Color of nitric acid is light yellow due to the presence of
A.	NO
B.	NO₂
C.	N₂H₅
D.	NH₃
Answer» C. N₂H₅

Discussion

1893.	5-10-5 fertilisers mean that they contain
A.	5, 10, 5% respectively of N₂, P₂O₅ and K₂O.
B.	only 5 to 10% active fertiliser constituents.
C.	5 to 10% filler & carrier of soil conditioners.
D.	none of these.
Answer» B. only 5 to 10% active fertiliser constituents.

Discussion

1894.	Urea is formed only
A.	in liquid phase
B.	in vapour phase
C.	at very high temperature
D.	at very low pressure (vacuum)
Answer» B. in vapour phase

Discussion

1895.	Dehydration of ammonium carbamate (to produce urea) is a/an __________ reaction.
A.	reversible
B.	catalytic
C.	exothermic
D.	endothermic
Answer» E.

Discussion

1896.	Electric process as compared to wet process (for the manufacture of phosphoric acid)
A.	can use only high grade phosphate rock.
B.	is used less frequently.
C.	produces a valuable by-product called gypsum.
D.	is weak acid process.
Answer» C. produces a valuable by-product called gypsum.

Discussion

1897.	Excessive use of chemical fertilisers causes shrivelling of the roots and wilting of the plant, because the
A.	osmotic pressure of the soil water becomes less than that of the plant sap.
B.	soil becomes too alkaline.
C.	osmotic pressure of the soil water becomes higher than that of the plant sap.
D.	soil becomes too acidic.
Answer» D. soil becomes too acidic.

Discussion

1898.	Naphtha in a fertiliser plant is used as a source of
A.	fuel
B.	H₂
C.	N₂
D.	O₂
Answer» C. N₂

Discussion

1899.	Urea is a better fertilizer than ammonium sulphate, because
A.	it is cheaper.
B.	nitrogen content is higher.
C.	it is not poisonous.
D.	it is easy to manufacture.
Answer» C. it is not poisonous.

Discussion

1900.	Yield of elemental phosphorous from rock phosphate is about __________ percent.
A.	1-2
B.	15-25
C.	40-45
D.	60-65
Answer» C. 40-45

Discussion

Explore topic-wise MCQs in Current Affairs.

The ratio of the length to breadth of a wooden float, is

The following proportion of the ingredients of concrete mix, is not in conformation to arbitrary method of proportioning

Proper proportioning of concrete, ensures

The maximum amount of dust which may be permitted in aggregates is

An aggregate is said to be flaky if its least dimension is less than

Construction joints are provided

The high strength of rapid hardening cement at early stage, is due to its

Slump test is done for

For the construction of cement concrete floor, the maximum permissible size of aggregate, is

Curing a concrete for long period ensures better

If 20 kg of coarse aggregate is sieved through 80 mm, 40 mm, 20 mm, 10 mm, 4.75 mm, 2.36 mm, 1.18 mm, 600 micron, 300 micron and 150 micron standard sieves and the weights retained are 0 kg, 2 kg, 8 kg, 6 kg, 4 kg respectively, the fineness modulus of the aggregate, is

The commonly used material in the manufacture of cement is

Workability improved by adding

Hydration of cement is due to chemical action of water with

The standard sand now a days used in India, is obtained from

To ensure constant moisture content in aggregates

Permissible compressive strength of M 300 concrete grade is

To obtain cement dry powder, lime stones and shales or their slurry, is burnt in a rotary kiln at a temperature between

After casting, an ordinary cement concrete on drying

The risk of segregation is more for

According to I.S. : 456, the number of grades of concrete mixes, is

The mixture of different ingredients of cement, is burnt at

For ensuring quality of concrete, use

The maximum percentage of chemical ingredient of cement is that of

The aggregate impact value of the aggregate used in

Placing of concrete should preferably be done at a temperature of

Specified compressive strengh of concrete is obtained from cube tests at the end of

While compacting the concrete by a mechanical vibrator, the slump should not exceed

Curing

The bulk density of aggregates does not depend upon :

Heating of orthophosphoric acid to 250°C produces

During conversion of ammonium carbamate into urea, presence of large excess of water

H₃PO₄ is the chemical formula of __________ phosphoric acid.

Action of phosphoric acid on rock phosphate produces

Ammonium nitrate (a fertiliser) is coated with limestone powder to

The concentration (weight %) of nitric acid produced by the oxidation of ammonia and absorption of nitrogen oxides with water is about __________ percent.

CO₂ present in reformed gas (obtained by steam reforming of naphtha) is removed by absorbing in

Calcium ammonium nitrate (CAN) is

Urea is represented as

Fertiliser plants get their N₂ requirements

Catalytic ammonia synthesis reaction as in Haber's process is

Color of nitric acid is light yellow due to the presence of

5-10-5 fertilisers mean that they contain

Urea is formed only

Dehydration of ammonium carbamate (to produce urea) is a/an __________ reaction.

Electric process as compared to wet process (for the manufacture of phosphoric acid)

Excessive use of chemical fertilisers causes shrivelling of the roots and wilting of the plant, because the

Naphtha in a fertiliser plant is used as a source of

Urea is a better fertilizer than ammonium sulphate, because

Yield of elemental phosphorous from rock phosphate is about __________ percent.