281. An ideal fluid is

A.Similar to perfect gas

B.One which obeys Newton's law of viscosity

C.Frictionless and incompressible

D.Very viscous

282. If a mouthpiece is running full at the outlet, the vacuum created at vena-contracta

A.Increases velocity of jet

B.Decreases velocity of jet

C.Decreases the discharge

D.Decreases the value of coefficient of contraction

283. Vertical distribution of velocity in an open channel for laminar flow can be assumed as

A.Logarithmic

B.Parabolic

C.Straight line (constant)

D.Hyperbolic

284. Vertical distribution of velocity in an open channel for turbulent flow can be assumed as

A.Logarithmic

B.Parabolic

C.Straight line (constant)

D.Hyperbolic

285. The most economical channel section is one for which the following parameter is maximum for a given, cross sectional area

A.Velocity

B.Discharge

C.Depth

D.Wetted perimeter

286. The most economical section of a rectangular channel for maximum discharge is obtained when its depth is equal to

A.Half the breadth

B.Twice the breadth

C.Same as the breadth

D.3th the breadth 4

287. One dimensional flow is

A.Restricted to flow in a straight line

B.Uniform flow

C.One which neglects changes in a transverse direction

D.The most general flow

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