# Fluid Mechanics Questions and Answers – Most Economic Trapezoidal Section

This set of Fluid Mechanics Multiple Choice Questions & Answers (MCQs) focuses on “Most Economic Trapezoidal Section”.

1. Determine the top width length of the most economical trapezoidal channel section having depth y and side slope Z.
a) $$\sqrt{1+Z^2}$$
b) $$\frac{y}{2} \sqrt{1+Z^2}$$
c) y$$\sqrt{1+Z^2}$$
d) 2y$$\sqrt{1+Z^2}$$

2. Estimate the hydraulic radius of the most economical trapezoidal channel section having depth y and side slope Z.
a) y2
b) y
c) 2y
d) 3y

3. The top width of a most economical trapezoidal channel section is 7m and the side slope of the channel is 1H:2V, determine the depth of the channel section.
a) 2.13m
b) 3.13m
c) 4.13m
d) 5.13m

4. The top width of a most economical trapezoidal channel section is 8m, determine the hydraulic radius of the channel if the side slope is 1H:3V.
a) 1.8m
b) 1.9m
c) 2.0m
d) 2.1m

5. The base of the most economical trapezoidal channel section is 6m and the side slope is 1H:2V, calculate the maximum discharge through the channel if the bed slope is 1 in 1000 and C = 50.
a) 120.61 m3/s
b) 110.61 m3/s
c) 100.61 m3/s
d) 90.61 m3/s

Note: Join free Sanfoundry classes at Telegram or Youtube

6. Calculate the maximum discharge through a trapezoidal section having depth 3m, side slope 1H:4V and bed slope of 1 in 2000. Given: n = 0.025.
a) 19.09 m3/s
b) 20.09 m3/s
c) 21.09 m3/s
d) 22.09 m3/s

7. The wetted area of a most economical trapezoidal section is 21.58m2, base width of 5m and side slope of 1H:3V. Calculate the maximum discharge through the channel if the C=60 and S0=1/500.
a) 56.32 m3/ s
b) 66.32 m3/ s
c) 76.32 m3/ s
d) 86.32 m3/ s

8. Calculate the depth of the most economical trapezoidal channel section having wetted area equal to 50m2 and the side slope of 1H:5V.
a) 3.21m
b) 4.21m
c) 5.21m
d) 6.21m

9. The wetted perimeter of the most economical trapezoidal section is 7.47m, the base width is 3m and has the side slope of 1H:2V.
a) 1m
b) 2m
c) 3m
d) 4m

10. Calculate the maximum discharge through a trapezoidal channel if the wetted perimeter is 6.24m, side slope of 1H:2V and base width of 4m. Given: C=55 and S0=1/1500.
a) 3.52 m3/s
b) 4.52 m3/s
c) 5.52 m3/s
d) 6.52 m3/s

11. The maximum discharge through the trapezoidal channel is 20 m3/s and the velocity of flow is 5 m/s. Calculate the base width of the channel if the side slope is 1H:4V.
a) 3.31m
b) 2.31m
c) 1.31m
d) 0.31m

12. What is the side slope for the most economic trapezoidal channel having depth y and base width B?
a) $$\frac{1}{\sqrt{2}}$$
b) $$\frac{1}{\sqrt{3}}$$
c) $$\frac{1}{2}$$
d) $$\frac{1}{3}$$

13. What is the angle made by the sloping side when the trapezoidal channel discharges to the maximum extent?
a) 30°
b) 45°
c) 60°
d) 90°

14. Calculate the maximum discharge through a trapezoidal channel if the depth is 5m.
a) 56.67 m3/s
b) 66.67 m3/s
c) 76.67 m3/s
d) 86.67 m3/s

15. If the side slope angle in a trapezoidal section is 45° and it discharges to the maximize extent, calculate the top width of the channel section. Given: y = 4m
a) 10.31m
b) 11.31m
c) 12.31m
d) 13.31m

Sanfoundry Global Education & Learning Series – Fluid Mechanics.

To practice all areas of Fluid Mechanics, here is complete set of 1000+ Multiple Choice Questions and Answers. 