Question

1.             Circle the correct answer of the following (True/False)
   1. Darcy’s velocity is a synonym to apparent velocity (T/F)
   2. The hydraulic conductivity of a porous media is a function of both porous media and fluid properties (T/F)
   3. Intrinsic permeability is related to the second power of the pore radius (T/F)
   4. Dynamic viscosity of a fluid is a synonym to kinematic viscosity (T/F)
   5. Dynamic viscosity of a fluid is a synonym to absolute viscosity (T/F)
   6. Average linear pore velocity is large than Darcy's velocity (T/F)
   7. Seepage velocity = pore water velocity = average linear velocity (T/F)
   8. Isolated water as dead-end pores or trapped gas don’t count when using effective porosity (T/F)
   9. Effective porosity is not available for flow (T/F)
   10. Productive aquifers should have high porosity and high transmissivity (T/F)
   11. Groundwater flows faster that surface water (T/F)
   12. Water table is the locus of points where water pressure is zero relative pressure (T/F)
   13. Aquiclude is a synonym to confining layer (T/F)
   14. Perched water table is a water table that forms below a restrictive layer near the soil surface (T/F)
   15. In confined aquifer, hydraulic gradient equals to the slope of the piezometric surface (T/F)
   16. In unconfined aquifer, hydraulic gradient is the water deriving force and equals to slope of water table surface (T/F)
   17. oceans lose more water by evaporation than they gain by precipitation (T/F)
   18. Land surfaces receive more water as precipitation than they lose by evapotranspiration (T/F)
   19. Residence time of lakes is lower than that in rivers (T/F)
   20. Residence time is the time required to replace a given ocean constituent by river supply (T/F)
   21. Residence time tells how quickly or slowly a river constituent can respond to a change in the constituent supply or removal rates (T/F)

Answer 1

1. Darcy's velocity is not the actual velocity of the flow of water through the pores. It is only an apparent velocity through the bulk of soil medium. Hence the statement is TRUE.

2. The hydraulic conductivity of the porous media is dependent both on the medium properties as well as the fluid property. Hence the statement is TRUE.

3. The absolute permeability of the porous media is inversely proportional to the square of cross sectional area of the sample and not the pore. So the answer is FALSE.

4. Dynamic viscosity is not a synonym of kinematic viscosity, it is that of absolute viscosity. So the statement is FALSE.

5. Dynamic viscosity is a synonym of absolute viscosity. So the statement is TRUE.

6. The average velocity through which the fluid moves in the pores is greater than the Darcy's velocity. So the statement is TRUE.

7. Seepage velocity is the actual velocity of the fluid through the pores. So the statement is TRUE.

8. Effective porosity considers only the bound water. So isolated water is not considered. The statement is TRUE.

9. Effective porosity is that which is available for the flow. So the statement is FALSE.

10. The aquifers with high porosity and transmissivity have higher yields. The statement is TRUE.