Cross regulators in main canals are provided______.

Civil Engineering : Irrigation - Quiz(MCQ)

to overflow excessive flow water

to regulate water supply in the distributaries

to increase water head upstream when a main canal is running with low supplies

None of the above

Correct Answer : to increase water head upstream when a main canal is running with low supplies

Recently Updated in Irrigation Questions

Which type of lining is mixed and placed under temperature?

Dry Stone Lining

Shotcrete Lining

Cement Concrete Lining

Asphaltic Concrete Lining

Correct Answer : Option (D) : Asphaltic Concrete Lining

Explanation : Asphaltic concrete lining has been under evolution. It is used in very few places. This concrete is a careful mixture of asphalt and graded stone aggregate, and is mixed and applied under elevated temperature. This is a flexible lining and readily confirms to subgrade.

Calculate hydraulic mean depth for concrete-lined channel to carry a discharge of 350 cumecs at a slope of 1 in 5000. The value of manning’s constant for the lining is 0.015. The side slopes of a channel may be taken as 1.5:1. Assume limiting velocity in the channel as 2m/sec.

2.20 m

2.40 m

2.60 m

2.80 m

Correct Answer : Option (D) : 2.80 m

Explaination : Using Manning’s equation: V = 1/n.R2/3.S½
2 = 1/0.015 x Râ…” x 1/5000½
R = 2.80 m.

What is the maximum permissible velocity in Cement concrete lining (Unreinforced) as per Indian Standards?

1.2 to 1.8 m/sec

2 to 2.5 m/sec

1.5 to 2 m/sec

1.5 to 2.5 m/sec

Correct Answer : Option (B) : 2 to 2.5 m/sec

Explanation : The maximum permissible velocity for unreinforced cement concrete lining is 2.0 to 2.5 m/sec. For Boulder lining, the maximum permissible velocity is 1.5 m/sec.