631. Permissible velocity of water flowing through concrete lined tunnel is usually __________________?

A. 3 – 4m/sec
B. 4 – 5m/sec
C. 5 – 6m/sec
D. 6 – 7m/sec

632. The depth of flow at which the energy is maximum is called ____________________?

A. Super critical depth
B. Sub-critical depth
C. Critical depth
D. All are correct

633. Water application efficiency increases if the plot to be irrigated is__________________?

A. Circular
B. Square
C. Rectangle
D. All are correct

634. Water available above the top of root zone of plants is about 15% of soil moisture contents, is mostly not available to plants celled_________________?

A. Capillary water
B. Irrigation water
C. Effective water
D. Hygroscopic water

635. Wilting point is that limit after that the crop starts feeding up and no water is available for plant, this point occurs after _________________?

A. 30% water available
B. 25% water available
C. 20% water available
D. All are correct

636. Estimated quantity of global water is __________which covers about 70% of earth?

A. 1.30x109km3
B. 1.32x109km3
C. 1.33x109km3
D. 1.35x109km3

637. velocity of gases is measured with a _____________________?

A. Hot wire manometer
B. Hot wire anemometer
C. Barometer
D. All are correct

638. From a water fall, if water is falling down at the rate of 100 N/sec: on the blades of a turbine when the height of fall is 100 m the power delivered to turbine will be______________?

A. 1000 kw
B. 10,000 kw
C. 100 kw
D. 5000 kw

639. Mercury does not wet the glass because of its property of ______________________?

A. Capillary
B. Surface tension
C. Compressibility
D. Viscosity

640. A type of flow in which water particles, while moving in the direction of flow, rotate about their mass centre is called _________________?

A.Turbulent flow
B. Laminar flow
C. Rotational flow
D. Circular flow