43.  From the surface of reservoir, evaporation may be minimised by sprinkling
A. Spirit
B. Hydrochloric acid
C. Acetyl alcohol
D. Methane

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44.  The factor to be considered for the source of city water supply, is
A. quantity and quality of the available water
B. elevation of the source of water
C. general terrain intervening the area
D. all the above.

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45.  Pick up the incorrect statement from the following :
A. Porosity of clay sand soil is 45%
B. Porosity of pure sand is 35%
C. Porosity of sand stone is up to 15%
D. None of these.

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46.  Shales are
A. porous
B. permeable
C. porous and permeable
D. porous but not permeable

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47.  The capability of a soil mass of full width and depth to transmit water, is known
A. porosity
B. permeability
C. transmissibility
D. none of these.

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48.  For determining the velocity of flow of underground water, the most commonly used non-empirical formula is
A. Darcy's formula
B. Slichter's formula
C. Hazen's formula
D. Lacy's formula.

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49.  The coefficient of permeability of soils, is generally expressed in
A. cm/sec
B. cm/minute
C. cm2/sec
D. cm2/minute.

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