Quiz: Civil Engineering 25 Sep 2020

Quiz: Civil Engineering
Exam: SSC-JE
Topic: Building, Material & Construction

Each question carries 1 mark
Negative marking: 1/4 mark
Time: 10 Minutes

Q1. Le Chatelier’s device is used for determining the
(a) setting time of cement
(b) soundness of cement
(c) tensile strength of cement
(d) compressive strength of cement

Q2. Alumina content in a good brick earth must be at least.
(a) 50%
(b) 35%
(c) 20%
(d) 40%

Q3. Which of the following quality of timber can improved using Abel’s process?
(a) Durability
(b) Fire Resistance
(c) chemical resistance
(d) Strength

Q4. The small area on painted surface enclosed by hair line cracks are known as:
(a) Blistering
(b) Crazing
(c) Wrinkling
(d) Chalking

Q5. The defect in timber that causes longitudinal separation of woods between the annular rings is known as___________.
(a) Knots
(b) Rind gall
(c) Shakes
(d) Twisted fibers

Q6. Initial setting time is maximum for
(a) Portland-pozzolana cement
(b) Portland-slag cement
(c) low-heat Portland cement
(d) high strength Portland cement

Q7. Consider the following statements kiln seasoning of timber results in
(a) reduced density
(b) reduced life
(c) dimensional stability
Which of these statements is/are correct?
(a) a, b and c
(b) a only
(c) b and c
(d) a and c

Q8. A first class brick when immersed in cold water for 24 hours should not absorb water more than:
(a) 15 %
(b) 20%
(c) 22%
(d) 25%

Q9. Temperature that can be resisted by TMT bars without any loss of strength is:
(a) 50o C
(b) 200 o C
(c) 500 o C
(d) 1000 o C

Q10. Number of bricks required for one cubic meter of brick masonry is:
(a) 400
(b) 500
(c) 450
(d) 550

SOLUTIONS

S1. Ans.(b)
Sol. Le – chatelier’s device is used for determining the soundness of cement due to Presence of free lime while autoclave test is used for determining the soundness of cement due to lime and magnesia both. A sample of cement is said to be sound when it does not contain free lime and magnesia.

S2. Ans.(c)
Sol. Percentage of various ingredients in a good brick earth is as follow-
Silica → 50% to 60%
Alumina → 20% to 30%
Lime → >5%
Oxide of Iron → 5% to 6%
Magnesium → less than 1%

S3. Ans.(b)
Sol. Timber surface is coated with solution of sodium silicate (Na_2 SiO_3 ) which increase the resistance against fire. This process is called sir Abel’s process.

S4. Ans.(c)
Sol. Wrinkling → These are the hair line cracks on small area of painted surface.

S5. Ans.(c)
Sol. Shakes → It is longitudinal cracks which partially or completely separates the fibres.
(a) Heart shakes → cracks run from pith to sapwood.
(b) Cup shakes → Appears as partly or completely separates annual rings from one another.
(c) Ring shakes → Appears as completely separates annual rings.
(d) Star shakes → cracks run from bark to sap wood.

S6. Ans.(c)
Sol. Low heat Portland cement is less reactive than OPC. The initial settling time is about one hour i.e. greater than that of OPC and final setting time is about 10 hours.

S7. Ans.(d)
Sol. Seasoning of timber is done to remove the sap from the timber.
1. Kiln seasoning of timber results in-
2. Reduce density of timber
3. Increases the life of timber
4. Provide dimensional stability
5. Reduce the weight
6. Reduce the shrinkage and warping
The moisture content in a well seasoned timber is about 10-12%.

S8. Ans.(b)
Sol. A first class brick when immersed in water for 24 hours should not absorb water more than 20% While second class brick should not absorb more than 22% water when immersed in water for 24 hours.

S9. Ans.(c)
Sol. Thermo mechanically treated (TMT) bar can resist temperature upto 500°C without any loss of strength.

S10. Ans.(b)
Sol. Size of modular brick = 0.2 × 0.1 × 0.1 m³
Then no. of brick in 1m³ = (1m^3)/(0.2×0.1×0.1m^3 )
= 500 bricks.

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