SSC-Junior Engineer (Civil & Structural) Online Exam 2018 (Part-IV)

Total Questions: 50

31. Wind load analysis can be done by using:

Correct Answer: B. IS 875 - part 3
Solution:

(Part-I)

  • Dead loads: These are the permanent loads which are always present. Dead loads includes, the self-weight of walls, floor, beams, column etc.

Plain cement concrete = 24 kN/m³
Reinforced cement concrete = 25 kN/m³.

  • Imposed load: Live loads on floors and roofs consists of all the loads which are temporarily placed on the structure.
  • Wind load: The force exerted by the horizontal component of wind to be considered in the design of structures. It depends upon the velocity of wind, shape and size of the structure.
  • Snow load: The structure which are located in the regions where snowfall is very common, are to be designed considering the snow load also.

32. The longitudinal coefficient of friction on highway for calculation of stopping distance in geometrical design is:

Correct Answer: D. 0.35 to 0.4
Solution:The frictional resistance developed between road and tyres or the skid resistance depends on the type and condition of the road surface and the tyres. The braking distance increases with decrease in skid resistance.

IRC specified a design friction coefficient of 0.35 to 0.4 depending upon the speed to be used for finding the braking distance in the calculation of stopping sight distance.

Coefficient of lateral friction as 0.15 is useful in horizontal curve design.

33. If crest length is equal to the width of the channel then it is called:

Correct Answer: C. suppressed weir
Solution:The discharge over a rectangular weir is given by:

with velocity of approach

with velocity of approach
Equation (i) and (ii) are applicable to the weir of notch for which the crest length is equal to the width of the channel. This type of weir is called Suppressed weir. But if the weir is not suppressed, the effect of end contraction will be taken into account.

34. For a circular column with diameter 'd' subjected to a compressive load 'W' at an eccentricity 'e', the diameter of core of section is:

Correct Answer: C. d/4
Solution:The area through which load must pass without developing tensile stress is called core or kern.

Middle fourth rule:

35. Which of the following dams is classified based on structural design?

Correct Answer: B. Gravity dam
Solution:Dams are classified based on their use, hydraulic design and materials of construction. Table gives the types of dams under each category.
Main ClassificationSub-classification
Based on use of functionStorage dams, diversion dams, detention dams
Based on structural actionGravity dams, non-gravity dams
Based on hydraulic designOverflow dams, non-overflow dams
Based on rigidityRigid dams (solid masonry, concrete gravity, arch dam, buttress dam, steel dam), non-rigid dams (earth, rockfill, combined earth-rockfill dams)
Based on materials of constructionMasonry dam, concrete dam, earth dam, rockfill dam, timber dam, steel dam, combined concrete-cum-earth dam, composite dam

36. In a geodetic survey the surface of the earth is considered:

Correct Answer: D. Curved
Solution:Geodetic surveying is that type of surveying where the curvature of earth is considered. It is essential if the area of survey is quite large. Actual curvature of the earth is taken into account in this type of survey.

The lines on the earth surface are curved; and triangles are spherical. It therefore, invites spherical trigonometry. Science of geodesy is required in this type of survey. The main object of geodetic surveying is to determine the precise location of widely spaced on the surface of the earth.

37. The dimensions for special shape of clay bricks are given in:

Correct Answer: C. IS 6165-1971
Solution:
  • IS 6165-1971-Dimensions for special shapes of clay bricks.
  • IS 2212-1991-Brick work code for practice.
  • IS 4860-1968-Specification for acid-resistant bricks.
  • IS 5779-1986-Specification for burnt clay soiling bricks.
  • IS 4885-1988-Specification for sewer bricks.
  • IS 11650-1991-Guide for manufacture of common burnt clay building bricks by semi-mechanized process.
  • IS 13767-1993-Burnt clay fly ash building bricks.

38. The colour of Stale and septic sewage is ________.

Correct Answer: A. black or dark brown
Solution:Colour: The colour of sewage can normally be detected by the naked eye, and it indicates the freshness of sewage. If its colour is yellowish, grey, or light brown, it indicates fresh sewage. However if the colour is black or dark brown, it indicates stale and septic sewage. Other colours, may also be formed due to the presence of some specific industrial wastes.

39. Aerobic attached growth process is classified under:

Correct Answer: A. biological treatment
Solution:
  • Aerobic attached growth process is classified under biological treatment.
  • The biological unit process of sewage is a secondary treatment which involves stabilizing and rendering harmless very-fine suspended matter colloids and dissolved solids of the sewage.
  • The biological unit process are broadly classified as attached growth systems and suspended growth systems.
  • Aerobic attached growth systems are the intermittent and filters, the contact beds, the trickling filters and rotating biological contactors.
  • Aerobic suspended growth system are of two types: one in which part of the sludge is recirculated as in the case of the activated sludge process and second, which do not have sludge recycle e.g. aerated lagoons.

40. The binding material in the mortar is also called:

Correct Answer: C. matrix
Solution:The term mortar is used to indicate a paste prepared by adding required quantity of water to a mixture of binding material (cement or lime) and fine aggregate (sand). The above two components of mortar, namely, the binding material and fine aggregate are some times referred to as the matrix and adulterant respectively. The matrix binds the particles of the adulterant.

The durability, quality and strength of mortar will mainly depend on the quantity and quality of the matrix. The combined effect of the two components of mortar is that the mass is able to bind the bricks or stones firmly.