621. An earth embankment built on one or both sides of a river, some distance away from its banks to control flood is called _______________?

A. Dyke
B. Embankment
C. Marginal embankment
D. Flood protective bund

622. A pipe flowing full, the liquid particles in the pipe has maximum velocity at __________________?

A. Top of pipe
B. Centre of pipe
C. Bottom of pipe
D. All are correct

623. The hydraulic gradient line (H.G.L)represents the sum of_________________?

A. Pressure head + datum head
B. Pressure head + velocity head
C. Velocity head
D. Water surface

624. The precipitation that occurs because of frontal disturbances during the movement of barometric low pressure is called ____________________?

A. Hurricane
B. Cyclonic
C. Orographic
D. Convective

625. An instrument used for measuring pressure head, generally made up of a small pipe tapped into the side of conduit is called ___________________?

A. Pilot tube
B. Piezometer
C. Manometer
D. All are correct

626. hail is precipitation in the form of balls or lumps of ice of size greater than _______________ formed by alternate freezing & melting?

A. 5 mm diameter
B. 10 mm diameter
C. 15 mm diameter
D. 20 mm diameter

627. The depth of root zone for rice crop is about___________________?

A. 70 cm
B. 80 cm
C. 90 cm
D. 100 cm

628. A flow of water for a certain discharge when total energy of flow i.e. sum of potential, kinetic and pressure energies is minimum is called_______________________?

A. Shooting flow
B. Critical flow
C. Sub-critical flow
D. Normal flow

629. The angle between a head regulator and entrance of water, for smooth entry of water in a canal is kept as _________________?

A. 90°
B. 100°
C. 110°
D. 120°

630. A closed conduct or barrel used used for supplying water under high pressure to a turbine to generate electricity is called __________________?

A. A tunnel
B. Penstock
C. Chute
D. Syphon