Canal Falls MCQs : This section focuses on the "Canal Falls" in Irrigation Engineering. These Multiple Choice Questions (MCQs) should be practiced to improve the Irrigation Engineering skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.
Canal fall is a solid masonry structure which is constructed on the canal if the natural ground slope is steeper than the designed channel bed slope.
C. Can be true or false
D. Can not say
Explanation: True, Canal fall is a solid masonry structure which is constructed on the canal if the natural ground slope is steeper than the designed channel bed slope.
___________ is the combination of convex and concave curves.
B. Ogee curve
C. Stepped falls
D. Trapezoidal notch falls
Explanation: Ogee curve is the combination of convex and concave curves.
_________ consists a long sloping glacis.
A. Well type falls
B. Simple vertical drop falls
C. Rapid fall
D. Montague type falls
Explanation: Rapid fall consists a long sloping glacis. It is constructed if the available natural ground surface is plane and long.
Well type falls are also called as?
A. English falls
B. Montague type falls
C. Straight glacis falls
D. Syphon drop falls
Explanation: Well type falls are also called as syphon drop falls. In this case, an inlet well with pipe at its bottom is constructed in upstream.
How many types of falls are present?
Explanation: Since the idea of the construction of falls various types of falls have been designed. Some important falls are ogee falls, rapids, trapezoidal notch falls, simple vertical drop type and sarda type falls, straight glacis falls, Montague type falls and inglis falls.
Canal drops are provided to _______________
A. dissipate the excess energy
B. increase the driving head of flow of water
C. dissipate excess land slope
D. dissipate inadequate land slope
Explanation: when a canal fall or drop is provided at a suitable section, it brings down the canal bed line. In this process, water comes down with a great force and all the potential energy is converted into kinetic energy. The excess energy of the flow is destroyed with some suitable energy dissipation method.
Which of the following statement is wrong?
A. In a trapezoidal notch fall, the top width of the notch is kept between 3/4th to full water depth above the sill of the notch
B. Energy dissipators are provided for small discharges
C. A cylinder fall is popularly known as syphon well drop
D. The syphon fall is designed to maintain a fixed supply level in the channel
Explanation: In syphon well drops, the downstream well is provided for discharges greater than 0.29 cumecs. A trapezoidal notch is constructed in the steining of the well, the water falls into the inlet well from where it emerges near the bottom dissipating its energy in turbulence inside the well.
In case of design of sarda type fall the length of crest is kept equal to ____________
A. thickness of the Canal
B. bed Width of the Canal
C. water Depth in the Canal
D. hydraulic Jump on the fall
Explanation: In this case of designing a sarda type fall fluming is not possible, therefore the length of the crest is kept equal to the bed width of the canal.
What number of major defects does the ogee fall have?
Explanation: Ogee fall has two major defects. Heavy drawdown occurs on the upstream side, which results in lower depths, higher velocities and bed erosion. The kinetic energy of the flow will not be dissipated due to smooth transition, causing erosion on downstream bed and banks.
Trapezoidal falls are very economical and suitable for low discharges.
C. Can be yes or no
D. Can not say
Explanation: Yes, Trapezoidal falls are very economical and suitable for low discharges.