Soil Mechanics - Permeability of Soil

Q.1. In terms of permeability of soil, following statement is true
(a)  clays>silts>sands
(b)  silts>sands>clays
(c)  sands>silts>clays
(d)  none of these

Q.2. Match List-I with List-II and select correct answer by using the codes given below the lists.
            List-I
A.     Gravels
B.     Sand
C.     Silt
D.     Clays

List-II
1.      10-7 cm/sec.
2.      10-6 cm/sec.
3.      10-1 cm/sec.
4.      10 cm/sec.
(a)  A1,B2,C3,D4
(b)  A3,B4,C1,D2
(c)  A4,B3,C2,D1
(d)  A2,B4,C3,D1 (IES 1992)

Q.3. Constant head permeameter is used to test permeability of
(a)  silt
(b)  clay
(c)  coarse sand
(d)  fine sand

Q.4. Falling head permeameter is used to test permeability of
(a)  silt
(b)  clay
(c)  fine sand
(d)  all these

Q.5. For practically impervious type of soil, the coefficient of permeability is determined using
(a)  variable head test
(b)  constant head test
(c)  consolidation test
(d)  pumping test (IES 1993)

Q.6. Using falling head permeameter, value of permeability(k) is determined from the formula
(a)  \frac{{a.L}}{{A({t_2} - {t_1})}}.{\log _e}\frac{{{h_2}}}{{{h_1}}}
(b)  \frac{{a.L}}{{A({t_2} - {t_1})}}.{\log _e}\frac{{{h_1}}}{{{h_2}}}
(c)  \frac{{A.L}}{{a({t_2} - {t_1})}}.{\log _e}\frac{{{h_2}}}{{{h_1}}}
(d)  \frac{{a.L}}{{A({t_2} - {t_1})}}.{\log _{10}}\frac{{{h_2}}}{{{h_1}}}
            
Where t2 - t1 is the time taken for the head to fall from h1 to h2, A is cross-sectional area of sample, a is cross-sectional area of the standpipe and L is height of sample.

Q.7. If during a permeability test on a soil sample with a falling head permeameter, equal time  intervals are noted for drop of head from h1 to h2 and again from h2 to h3, then which one of the following relations would hold good?
(a)  h12 = h2h3
(b)  h22 = h1h3
(c)  h32 = h2h1
(d)  none of these (IES 1995)

Q.8. In an unconfined flow pumping test, acquifer is
(a)  underlain by permeable stratum
(b)  underlain by impermeable stratum
(c)  contained between permeable and impermeable stratum
(d)  none of these

Q.9. In a confined flow pumping test, acquifer is
(a)  underlain by impermeable stratum
(b)  underlain by permeable stratum
(c)  contained between impermeable and permeable stratum
(d)  contained between impermeable strata, above and below

Q.10. In an unconfined flow pumping set, pumping generates a radial flow
(a)  towards the filter well
(b)  beyond filter well
(c)  towards acquifer
(d)  towards impermeable stratum

Answers:
1. c
2. c
3. c
4. d
5. d
6. b
7. b
8. b
9. d
10. a


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These questions are taken from the book "Objective Questions (Civil Engineering)". The Kindle edition of this book is available at just ₹ 99/- only! 

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