Void Ratio MCQ – Geotechnical Engineering

31. The optimum moisture content of a soil is 17%. Its specific gravity is 2.68. The theoretical maximum dry density of the soil corresponding zero air voids at optimum water content is

  1. 1.84 g/cm3
  2. 0.06 g/cm3
  3. 3.68 g/cm3
  4. 1.50 g/cm3
Answer
Answer. a

32. A soil has a bulk density of 1.80 gm/cm3 at a water content of 5%. If the void ratio remains constant, then its bulk density for a water content of 10% will be

  1. 1.88 gm/cm3
  2. 1.98 gm/cm3
  3. 1.70 gm/cm3
  4. 1.80 gm/cm3
Answer
Answer. a

33. A soil sample having a void ratio of 1.3, water content of 50% and a specific gravity of 2.60, is in a state of

  1. partial saturation
  2. full saturation
  3. over saturation
  4. under saturation
Answer
Answer. b

34. A sand has a minimum void ratio of 0.41 and a maximum void ratio of 0.78. Its dry unit weight is 16.5 kN/m3. If the specific gravity of the solids is 2.65, the relative density of the sand is most nearly

  1. 0.40
  2. 0.55
  3. 0.80
  4. 0.65
Answer
Answer. b

35. The void ratio ‘e’ is defined as, when Vv = volume of the voids and Vs = volume of the solids

$\\a.\; e=\frac{V_{s}}{V_{v}}\\ b.\; e=\frac{V_{v}}{V_{s}}\\ c.\; e=\frac{V_{v}-V_{s}}{V_{s}}\\ d.\; e=\frac{1-V_{v}}{V_{s}}$

Answer
Answer. b

36. Which one of the following relations is NOT correct?

Consider e =void ratio, n = porosity, W = water content, S = degree of saturation, γsat = saturated unit weight of soil, γw = unit weight of water, γd = density, G= specifc gravity.

$\\a.\; e=\frac{wG}{S}\\ b.\; \gamma_{sat}=\frac{G+e}{1+e}\gamma_{w}\\ c.\; \gamma_{d}=\frac{G\gamma_{w}}{1+e}\\ d.\; e=\frac{1-n}{n}$

Answer
Answer. b

37. The voids ratio of a cohesionless soil sample in its loosest state is 1, while in its densest state it is 0.5. If the natural voids ratio of the deposit is 0.6, then the degree of density of the soil is

  1. 0.5
  2. 0.6
  3. 1
  4. 0.8
Answer
Answer. d

38. A dry soil has mass specific gravity of 1.35. if the specific gravity of solids is 2.7, then the void ratio will be

  1. 0.5
  2. 1.0
  3. 1.5
  4. 2.0
Answer
Answer. b

39. In a wet soil mass, air occupied 1/6 of its volume and water occupied 1/3 of its volume. The void ratio of the soil is

  1. 0.50
  2. 0.25
  3. 1.50
  4. 1.00
Answer
Answer. d

40. If the water content of a fully saturated soil mass is 100%, then the voids ratio of the sample is

  1. Less than specific gravity of soil
  2. Equal to specific gravity of soil
  3. Greater than specific gravity of soil
  4. Independent of specific gravity of soil
Answer
Answer. b