The scour depth D of a river during flood, may be calculated from the Lacey's equation

A D = 0.47 $$\left( {\frac{{\text{Q}}}{{\text{f}}}} \right)$$
B D = 0.47 $${\left( {\frac{{\text{Q}}}{{\text{f}}}} \right)^{\frac{1}{2}}}$$
C D = 0.47 $${\left( {\frac{{\text{Q}}}{{\text{f}}}} \right)^{\frac{1}{3}}}$$
D D = 0.47 $${\left( {\frac{{\text{Q}}}{{\text{f}}}} \right)^{\frac{2}{3}}}$$

Correct Answer: D = 0.47 $${\left( {\frac{{\text{Q}}}{{\text{f}}}} \right)^{\frac{1}{3}}}$$

Bissoy MCQ
#Civil Engineering #Irrigation Engineering

Related Questions

According to Lacey, depth of scour in a river depends upon the straightness of the reach. If D is the depth of scour in regime flow in a right angled bend, it is
A 1.25 D
B 1.50 D
C 1.75 D
D 2.00 D
If D is the depth of scour below original bed, then the width of launching apron is generally taken as
A 1.2 D
B 1.5 D
C 2.0 D
D 2.5 D
A swimming pool is initially filled to a depth of 96 inches. After 2 weeks, the depth has decreased to9212 inches. Assuming that the depth decreased at a constant rate, after how many days would the water depth have reached 9334 inches?
A 3
B 9
C 7
D 6
Scour valves are provided
A At street corners to control the flow of water
B At every depression and dead ends to drain out the waste water that may collect there
C At the foot of rising main along the slope to prevent back running of water
D At every summit of rising mains
Water flow in the river during flood can be categorised as the __________ flow.
A Unsteady uniform
B Unsteady non-uniform
C Steady uniform
D Steady non-uniform
Which category of river training work deals with flood control?
A Training for Sediment
B Low Water Training
C Training for Depth
D Training for Discharge
According to G.W. Pickles the effect of confining the flood water of a river between levee, is to increase
A Rate of flood wave
B Water surface elevation during floods
C Maximum discharge
D Surface slope of streams above the levied portion
The flood plain along river banks formed by newer alluvium is called:
A Meander
B River Valley
C Delta
D Khaddar
Lacey's equation for calculating flood discharge in rivers, is
A $${\text{V}} = 10.8\,{{\text{R}}^{\frac{1}{2}}}{{\text{S}}^{\frac{1}{2}}}$$
B $${\text{V}} = 10.8\,{{\text{R}}^{\frac{2}{3}}}{{\text{S}}^{\frac{1}{2}}}$$
C $${\text{V}} = 10.8\,{{\text{R}}^{\frac{2}{3}}}{{\text{S}}^{\frac{1}{3}}}$$
D $${\text{V}} = 10.8\,{{\text{R}}^{\frac{1}{3}}}{{\text{S}}^{\frac{2}{3}}}$$
If the depth of water in an open channel is greater than the critical depth, the flow is called
A turbulent flow
B critical flow
C torrential flow
D tranquil flow

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