166) A weir is said to be narrow-crested weir, if the width of the crest of the weir is __________ half the height of water above the weir crest.

167) The total pressure on an immersed surface inclined at an angle ? with the liquid surface is

168) Turbulent flow takes place at high velocities.

169) When a plate is immersed in a liquid parallel to the flow, it will be subjected to a pressure __________ that if the same plate is immersed perpendicular to the flow.

170) The hydraulic mean depth for a circular pipe of diameter (d) is