Question

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) The syphon fall is designed to maintain a fixed supply level in the channel

(c) A cylinder fall is popularly known as syphon well drop

(d) Energy dissipators are provided for small discharges

I have been asked this question during a job interview.

The above asked question is from Canal Falls in portion Canal Falls of Irrigation Engineering

Answer 1

Right option is (d) Energy dissipators are provided for small discharges

The 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.