Question

Which of the following statement is wrong?

(a) The velocity varies inversely with the Manning’s coefficient

(b) For unlined channels in good condition, the value of Manning’s coefficient is 0.015 for concrete

(c) Flatter slopes can be provided without silting on a lined channel

(d) The lining does not help to bring high areas under the command

I had been asked this question by my school principal while I was bunking the class.

My question is based upon Advantages of Lining topic in division Lining of Irrigation Canals and its Economics of Irrigation Engineering

Answer 1

Right choice is (d) The lining does not help to bring high areas under the command

For explanation I would say: The longitudinal slope of a lined canal is flatter than the corresponding unlined canal. Flat slope raises the F.S.L of the lined canal and it brings high patches of the land under command.