169. Most economical section of a triangular channel, is
A. equilateral triangle
B. right angled triangle
C. isosceles triangle with 450 vertex angle
D. right angled triangle with equal sides.
170. Most economical section of a circular channel for maximum discharge
A. depth of water = 0.95 diameter of circular section
B. hydraulic mean depth = 0.286 diameter of circular section
C. wetted perimeter = 2.6 diameter of circular section
D. all the above.
171. Most economical section of a circular channel for maximum velocity, is if,
A. depth of water = 0.810 diameter
B. hydraulic mean depth = 0.304 diameter
C. wetted perimeter = 2.245 diameters
D. all the above.
172. The most efficient channel section, is
A. semi-circular
B. rectangular
C. triangular
D. half hexagon in the form of trapezoid.
173. Chezy's formula is used to determine
A. head loss due to friction in pipe
B. velocity of flow in pipe
C.- velocity of flow in open channels
D. none of these.
174. Pick up the correct statement from the following :
A. For tranquil flow h > NW: or v < ?2
B. For critical flow h = ?v
C. For torrential flow h > ?2 or v <
D. None of these.
175. The phenomenon occuring in an open channel when a rapidly flowing stream abruptly changes to a slowly flowing stream causing a distinct rise of liquid surface, is
A. water hammer
B. hydraulic jump
C. critical discharge
D. none of these.
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