RRB JE exam Civil Engineering Soil Important MCQs – 6

51. If the water table rises upto ground surface, then the
a)
 effective stress is reduced due to decrease in total stress only but pore water pressure does not change
b)
 effective stress is reduced due to increase in pore water pressure only but total stress does not change
c)
 total stress is reduced due to increase in pore water pressure only but effec-tive stress does not change
d)
 total stress is increased due to de-crease in pore water pressure but effective stress does not change
Correct Option:b

53. Quick sand is a
a)      type of sand

b)
 flow condition occurring in cohesive soils
c)
 flow condition occurring in cohesionless soils
d)
 flow condition occurring in both cohesive and cohesionless soils
Correct Option:a

54. The hydraulic head that would produce a quick condition in a sand stratum of thickness 1.5 m, specific gravity 2.67 and voids ratio 0.67 is equal to
a)
 1.0m
b)
 1.5 m
c)
 2.0 m
d)
 3m
Correct Option:b

55. Physical properties of a permeant which influence permeability are
a)
 viscosity only
b)
 unit weight only
c)
 both viscosity and unit weight
d) none of the above
Correct Option:c

56. Select the correct statement.
a)
 The greater the viscosity, the greater is permeability.
b)
 The greater the unit weight, the greater is permeability.
c)
 The greater the unit weight, the smaller is permeability.
d)
 Unit weight does not affect per-meability.
Correct Option:b

57. Effective stress on soil
a)
 increases voids ratio and decreases permeability
b)
 increases both voids ratio and permeability
c)
 decreases both voids ratio and permeability
d)
 decreases voids ratio and increases permeability
Correct Option:c

58. If the permeability of a soil is 0.8 mm/sec, the type of soil is
a)
 gravel
b)
 sand
c)
 silt
d)
 clay
Correct Option:b

59. Which of the following methods is more suitable for the determination of permeability of clayey soil ?
a)
 constant head method
b)
 falling head method
c)
 horizontal permeability test
d)
 none of the above
Correct Option:b

60. Which of the following methods is best suited for determination of permeability of coarse-grained soils ?
a)
 constant head method
b)
 falling head method
c)
 both the above
d)
 none of the above
Correct Option:a