SSC-JUNIOR ENGINEER (Civil & Structural) Online Exam 2019 (Part-III)

Total Questions: 50

21. In an open channel flow, for best efficiency of a rectangular section channel, ratio of bottom width to depth shall be:

Correct Answer: B. 2
Solution:For a rectangular channel, the geometric features are given by Eq. Therefore, keeping A constant, we can minimize P by setting its derivative with respect to the depth equal to zero, i.e.,

22. Concrete in the member represented by core test shall be considered acceptable if the average equivalent cube strength of cores is equal to at least _________ % of cube strength of the grade of concrete specified for the corresponding age.

Correct Answer: D. 85
Solution:The method of preparation of cores after drilling and the procedure of test are described in IS: 516-1959. As per IS: 456-2000 the concrete in the member represented by a core test shall be considered acceptable if the average equivalent cube strength of the cores is equal to at least 85 per cent of the cube strength of the grade of concrete specified for the corresponding age, and no individual core has a strength less than 75 per cent. The main drawback of this test is the difference in the intrinsic quality of concrete in structure and control specimens in the laboratory.

23. When the duration of lease is 99 years, it is called:

Correct Answer: B. long term lease
Solution:A 99-year lease was, under historic common law, the longest possible term of a lease of real property. It is no longer the law in most common law jurisdictions today, yet 99-year leases continue to be common as a matter of business practice and conventional wisdom.

24. Calculate the population by the end of 2011 by the arithmetical increase method.

YearPopulation
19511,00,000
19611,09,000
19711,16,000
19811,28,000
Correct Answer: B. 1,56,000
Solution:
YearPopulationIncrease in Population
19511,00,000—
19611,09,0009,000
19711,16,0007,000
19811,28,00012,000
Total28,000

25. A short RCC column is designed assuming maximum permissible axial compressive stresses in concrete and steel as:

Correct Answer: B.
Solution:All columns including the short axially loaded columns shall be designed with a minimum eccentricity. Moreover, the design strengths of concrete and steel are further reduced to 0.4 f꜀ₖ   and 0.67ᵧ, respectively, to take care of the minimum eccentricity of 0.05 times the lateral dimension.

26. Which of the following components of ordinary Portland cement is responsible for flash setting?

Correct Answer: C. C₃A
Solution:Tetracalcium alumino Ferrite, C₄AF: This is a fluxing agent which reduces the melting temperature of the raw materials in the kiln (from 1650°C to 1450°C). It hydrates rapidly but does not contribute much to the strength of the cement paste. By mixing these compounds appropriately, manufacturers can produce different types of cement to suit several construction environments.

27. A rectangular area of 12 km² is represented by 1.5 cm x 0.5 cm rectangle on a map. The scale of the map is :

Correct Answer: D. I : 400000
Solution:

28. Which of the following quantities is NOT measured in square meter?

Correct Answer: C. RCC work for staircase
Solution:No explanation given in the book

29. Which of the following is NOT true about PVC pipes?

Correct Answer: A. They possess low coefficient of expansion as compared to cast-iron or galvanized-iron pipes
Solution: Advantages of PVC pipes:
  • Good insulating properties and hence the temperature of water passing through such pipes is not affected by the outside temperatures.
  • Permit high, smooth and undiminished flow of water.
  • No problem of incrustation.
  • Possess high Hazen Williams Constant and it results into adoption of smaller size of PVC pipes as compare to the sizes of pipes of other conventional materials under similar conditions.
  • Prove to be economical as compare to other pipes of conventional materials such as asbestos cement, cast-iron and galvanize iron.
  • Provide resistance to a variety of chemicals.

30. The sight distance is defined as the :

Correct Answer: B. length of the roadway a driver can see ahead at any particular time.
Solution:Sight distance is the length of roadway ahead that is visible to the driver. The minimum sight distance available on a roadway should be sufficiently long to enable a vehicle travelling at or near the design speed to stop before reaching a stationary object in its path. Although greater length is desirable, sight distance at every point along the highway should be at least that required for a below average driver or vehicle to stop in this distance.