# Fluid Mechanics Questions and Answers – Gradually Varied Flow(GVF) – 3

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This set of Fluid Mechanics Objective Questions & Answers focuses on “Gradually Varied Flow(GVF) – 3”.

1. Determine the value of the hydraulic depth of a channel having dydx = 4×10-4 and dEdx = 3.73×10-4. Given:V = 1m/s
a) 0.5m
b) 1.5m
c) 2.5m
d) 3.5m

2. A rectangular channel has depth of 1m and width of 2m, calculate the rate of change of depth if the rate of change of specific energy is 2×10-5m. Given: Fr=0.48.
a) 0.60×10-5m
b) 1.60×10-5m
c) 2.60×10-5m
d) 3.60×10-5m

3. The top width of a triangular channel section is 6m and the side slope of the channel is 1H:4V, calculate the rate of change of specific energy if dydx = 2×10-5m and V=2 m/s
a) 1.86×10-5m
b) 2.86×10-5m
c) 3.86×10-5m
d) 4.86×10-5m

4. If dEdx = 2.5×10-4 m and dydx = 3.5×10-4 m, calculate the value of Fr.
a) 0.23
b) 0.33
c) 0.43
d) 0.53

5. The rate of change of specific energy is given by x2/2 and x ranges from 0 to 3, calculate the value of specific energy.
a) 2.5m
b) 3.5m
c) 4.5m
d) 5.5m

6. The rate of change of depth is given by 1/x2 and the rate of change of specific energy is given by 3x2 with x ranging from 0 to 0.2, calculate the value of Froude’s number.
a) 0.96
b) 0.97
c) 0.98
d) 0.99

7. The hydraulic depth of a channel is 0.94m and the velocity of flow is 2 m/s. Calculate the rate of change of depth if the rate of change of specific energy is 2.5×10-4m.
a) 2.33×10-4m
b) 3.33×10-4m
c) 4.33×10-4m
d) 5.33×10-4m

8. Calculate the value of Froude’s number for a rectangular channel having depth 1.5m and width 2.5m if the value of C = 30 and S0=1 in 1000.
a) 0.1
b) 0.2
c) 0.3
d) 0.4

9. The dynamic equation for the slope of water surface in a GVF is not valid for super critical flow.
a) True
b) False

10. If the ratio of dEdx and dydx is 0.2823, estimate the value of Froude’s number.
a) 0.65
b) 0.75
c) 0.85
d) 0.95 