Pick up the incorrect statement from the following A. Side walls of a venturi head flume are splayed out from the end of the throat at 1 : 10 for a length of 4.5 m B. Length of side walls should be such that the width of the flume is made equal to $${\frac{2}{3}^{{\text{rd}}}}$$ the bed width of the distributary C. Once the width of the flume becomes $${\frac{2}{3}^{{\text{rd}}}}$$ of the width of the distributary, the splayed walls are increased to 1 in 3 to get full bed width D. None of these

[amp_mcq option1=”Side walls of a venturi head flume are splayed out from the end of the throat at 1 : 10 for a length of 4.5 m” option2=”Length of side walls should be such that the width of the flume is made equal to $${\frac{2}{3}^{{\text{rd}}}}$$ the bed width of the distributary” option3=”Once the width of the flume becomes $${\frac{2}{3}^{{\text{rd}}}}$$ of the width of the distributary, the splayed walls are increased to 1 in 3 to get full bed width” option4=”None of these” correct=”option3″]

The correct answer is C.

The splayed walls of a venturi head flume are increased to 1 in 3 to get full bed width only after the width of the flume becomes $\frac{2}{3}$ of the width of the distributary. This is done to ensure that the flume has a smooth transition from the throat to the wider section.

Option A is correct. The side walls of a venturi head flume are splayed out from the end of the throat at 1 : 10 for a length of 4.5 m. This is done to reduce the velocity of the flow and to create a pressure differential between the throat and the wider section of the flume.

Option B is correct. The length of side walls should be such that the width of the flume is made equal to $\frac{2}{3}$ the bed width of the distributary. This is done to ensure that the flume has a sufficient capacity to carry the required discharge.

Option D is incorrect. All of the statements are correct except for statement C.