281.  Pick up the correct statement from the following.
A. The flow lines and equipotentials intersect at right angles to each other
B. The fields are approximately square but of different sizes
C. The hydraulic gradient will be more if the dimensions of the field are small
D. All the above.

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282.  A flow net is used to determine the following:
A. Seepage discharge
B. Hydrostaiac pressure
C. Seepage pressure
D. All the above.

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283.  For most of Indian rivers sands, the specific gravity of solid, is assumed
A.2.45
B.2.55
C.2.65
D. 2.75.

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284.  If Ss and n are the specific gravity of solids and porosity of soil then the critical exit gradient is
A. (1 + n) (Ss + 1)
B. (1 - n)(S- 1)
C. (1 + n) (.3 - 1)
D. (1 - n)(s+ 1)

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285.  The capillary fringe water is also known as
A. Vadose water
B. Gravity water
C. Suspended water
D. All the above.

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286.  Direct shear test is not preferred due to
A. quick drainage in a relatively thin thickness of the sample
B. quick dissipation of pore pressure developed in a relatively thin thickness of the sample
C. decrease of the area under shear gradually with the progress of the test
D. None of the above.

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287.  The tendency of sand to expand by applying the shearing load, is called
A. thixotropy
B. dilatancy
C. remoulding loss
D. degree of sensitivity.

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