317) The highest efficiency is obtained with a channel of __________ section.

318) A vessel of 4 m³ contains an oil which weighs 30 kN. The specific weight of the oil is

319) Coefficient of discharge Cd is equal to (where C_c = Coefficient of contraction, C_v = Coefficient of velocity, and C_r = Coefficient of resistance)

320) In an internal mouthpiece, if the jet after contraction does not touch the sides of the mouthpiece, then the mouthpiece is said to be

321) The value of coefficient of velocity for a sharp edged orifice __________ with the head of water.