Q. Calculate the Manning’s rugosity coefficient in a coarse alluvium gravel with D-75 size of 5 cm.

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Q. The manning’s coefficient for a lined trapezoidal channel with a bed slope of 1 in 4000 is 0.014 and it will be 0.028 if the channel is unlined. The area in the case of the lined section is 19.04 m² and for the unlined section is 29.09 m². What percentage of earthwork is saved in a lined section relative to an unlined section, when a hydraulically efficient section is used in both the cases?

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Q. Calculate the critical tractive stress if the median diameter of the sand bed is 1.0 mm.

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Q. Calculate the ratio of the tractive critical stress to the average shear stress if the water flows at a depth of 0.8 m in a wide stream having a bed slope of 1 in 3000. The median diameter of the sand bed is 2 mm.

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Q. Determine the shear stress required to move the single grain on the side slopes, if the critical shear stress required moving the similar grain on the horizontal bed is 2.91 N/m². Consider the angle of the side slope with the horizontal as 30° and the angle of repose of soil as 37°.

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Q. The shear stress required to move grain on the side slopes is less than the shear stress required to move the grain on the canal bed.

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Q. Design of alluvial channels in India is based on Kennedy and Lacey theories.

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Q. On what condition does the resistance equations of Chezy’s formula and manning’s formula are applicable?

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Q. What is the problem in India for artificial channels?

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Q.
The velocity of flow in a channel should not more or less, but instead it should be adequate.

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Q. What is the effect of scouring in channels?

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Q. What is the effect of silting in channels?

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Q. Which type of state is achievable in artificial channels but not in rivers?

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Q. On what basis for designing the regime state is obtained?

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Q. What vital factor is not considered in regime theories during the design of regime channels?

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Q. According to Kennedy the silting action in channels is due to?

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Q. Based on his research what factor is given by Kennedy for free silting and scouring actions in a channel?

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Q. Given to design the irrigation channel to carry 80 cumecs of discharge. The channel slope is 1 in 3000. The critical velocity ratio is 1.3. Take rugosity coefficient as 0.021.

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Q. Design a regime channel for a discharge of 90 cumecs and silt factor is 1.3 use Lacey’s Theory.

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Q. According to Lacey what factor is needed to have a true regime in an artificial channel?

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