Soil Mechanics - Permeability of Soil

1. Permeability(k) of soil by unconfined flow pumping test is given by the formula
(a) \frac{q}{{2\pi D}}.\frac{{{{\log }_e}({r_2}/{r_1})}}{{({h_2} - {h_1})}} 
(b) \frac{q}{\pi }.\frac{{{{\log }_e}({r_2}/{r_1})}}{{({h_2}^2 - {h_1}^2)}}
(c) \frac{q}{{2\pi D}}.\frac{{{{\log }_e}({r_2}/{r_1})}}{{({h_2}^2 - {h_1}^2)}}  
(d) \frac{q}{\pi }.\frac{{{{\log }_e}({r_2}/{r_1})}}{{({h_2} - {h_1})}}  

2. Permeability(k) of soil by confined flow pumping test is given by the formula
(a) \frac{q}{{2\pi D}}.\frac{{{{\log }_e}({r_2}/{r_1})}}{{({h_2} - {h_1})}}
(b) \frac{q}{\pi }.\frac{{{{\log }_e}({r_2}/{r_1})}}{{({h_2}^2 - {h_1}^2)}}
(c) \frac{q}{{2\pi D}}.\frac{{{{\log }_e}({r_2}/{r_1})}}{{({h_2}^2 - {h_1}^2)}} 
(d) \frac{q}{\pi }.\frac{{{{\log }_e}({r_2}/{r_1})}}{{({h_2} - {h_1})}}  

3. Relationship between permeability(k, cm/sec.) and grain size(D₁₀, in mm) is
(a) k = C/{D_{10}}^2  
(b) k = C/{D_{30}}^2  
(c) k = C{D_{30}}^2  
(d) k = C{D_{10}}^2
Where C is a constant ranging between 0.4 and 1.2.

4. Permeability of a soil is not affected by changes in temperature. This statement is
(a) true
(b) false
(c) partially true
(d) incomplete

5. Which of the following statement(s) is/are true
(a) greater the viscosity, lower the permeability
(b) permeability is not affected by temperature
(c) permeability is not affected by void ratio
(d) permeability is not affected by unit weight of water

6. Relationship between permeability coefficient(k) and void ratio(e) is
(a) {k_1}{k_2} = {e_1}{e_2}  
(b) {k_1}{e_1} = {k_2}{e_2}  
(c) {k_1}/{k_2} = {e_1}^2/{e_2}^2
(d) {k_1}{e_2} = {k_2}{e_1}  

7. Relationship between permeability coefficient(k) and void ratio(e) is
(a) \frac{{{k_1}}}{{{k_2}}} = \frac{{{e_1}^3}}{{1 + {e_1}}}:\frac{{{e_2}^3}}{{1 + {e_2}}}
(b) \frac{{{k_1}}}{{{k_2}}} = \frac{{{e_2}^3}}{{1 + {e_1}}}:\frac{{{e_1}^3}}{{1 + {e_2}}}  
(c) \frac{{{k_1}}}{{{k_2}}} = \frac{{{e_1}^2}}{{1 + {e_1}}}:\frac{{{e_2}^2}}{{1 + {e_2}}}  
(d) \frac{{{k_1}}}{{{k_2}}} = \frac{{{e_1}}}{{1 + {e_1}}}:\frac{{{e_2}}}{{1 + {e_2}}}  

8. For silt and clays, following relationship between permeability(k) and void ratio(e) holds good
(a) {\log _{10}}{k_1}:{\log _{10}}{k_2} = {e_2}:{e_1}  
(b) {\log _{10}}{k_1}:{\log _{10}}{k_2} = {e_1}:{e_2} 
(c) {\log _{10}}{k_2}:{\log _{10}}{k_1} = {e_2}:{e_1}  
(d) {\log _{10}}{k_1}:{\log _{10}}{k_2} = {e_2}^2:{e_1}^2  

9. Relationship among permeability coefficient(k), viscosity(η) and unit weight({\gamma _w}) is
(a) \frac{{{k_1}}}{{{k_2}}} = \frac{{{\gamma _{w1}}}}{{{\eta _1}}}:\frac{{{\gamma _{w2}}}}{{{\eta _2}}} 
(b) \frac{{{k_2}}}{{{k_1}}} = \frac{{{\gamma _{w1}}}}{{{\eta _1}}}:\frac{{{\gamma _{w2}}}}{{{\eta _2}}}  
(c) \frac{{{k_1}}}{{{k_2}}} = \frac{{{\gamma _{w1}}}}{{{\eta _2}}}:\frac{{{\gamma _{w2}}}}{{{\eta _1}}}  
(d) \frac{{{k_1}}}{{{k_2}}} = {\gamma _{w1}}{\eta _1}:{\gamma _{w2}}{\eta _2}  

10. Due to rise of temperature, the viscosity and unit weight of the percolating fluid are reduced to 80% and 98%, respectively. Percentage change in coefficient of permeability(k)
(a) 78.4%
(b) 22.5%
(c) 0 %
(d) none of these

Answers

    1. (b)    2. (a)    3. (d)    4. (b)    5. (a)
    6. (c)    7. (a)    8. (b)    9. (a)    10. (b)

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