Civil Engineering (CE) Exam > Civil Engineering (CE) Questions > A rectangular channel has 5 m width and 3 m ...
Start Learning for Free
A rectangular channel has 5 m width and 3 m water depth. If the bed slope of the channel is 1 in 1200, find the minimum width of throat in m, if Manning’s n = 0.02. (Report your answer upto two decimal place)
Correct answer is 'Range: 2.75 to 2.81'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Verified Answer
A rectangular channel has 5 m width and 3 m water depth. If the bed s...
Given B = 5 m, S = 1 in 1200, y = 3 m,
View all questions of this test
n = 0.02
Area = B × y = 5 × 3 = 15 m2
P = B+2y = 5+2×3 = 11m
When channel section is contracted to minimum width and for constant discharge Q, the flow over the contracted section will be critical flow and under assumption that no energy loss has taken place.
E2 = Ec = E1 (Since there is no energy loss)
Most Upvoted Answer
A rectangular channel has 5 m width and 3 m water depth. If the bed s...
Given data:
Width of rectangular channel (B) = 5 m
Depth of water (y) = 3 m
Bed slope (S) = 1 in 1200
Manning’s n (n) = 0.02
We need to find the minimum width of the throat (b) in m.
Formula used:
The formula used to find the minimum width of the throat is the continuity equation.
Q = A × V
Where,
Q = Discharge (m³/s)
A = Cross-sectional area of the flow (m²)
V = Velocity of flow (m/s)
A = B × y
Where,
A = Cross-sectional area of the flow (m²)
B = Width of the channel (m)
y = Depth of water (m)
V = (1/n) × R^2/3 × S^1/2
Where,
V = Velocity of flow (m/s)
n = Manning’s n
R = Hydraulic radius (m)
S = Bed slope (m/m)
R = A/P
Where,
R = Hydraulic radius (m)
A = Cross-sectional area of the flow (m²)
P = Wetted perimeter (m)
P = B + 2y
Calculation:
A = B × y
= 5 × 3
= 15 m²
P = B + 2y
= 5 + 2 × 3
= 11 m
R = A/P
= 15/11
= 1.36 m
V = (1/n) × R^2/3 × S^1/2
= (1/0.02) × (1.36)^2/3 × (1/1200)^1/2
= 1.57 m/s
Q = A × V
= 15 × 1.57
= 23.55 m³/s
For minimum width of the throat, the entire discharge should pass through the throat. Therefore, we use the continuity equation at the throat.
Q = b × y_throat × V_throat
Where,
b = Width of the throat (m)
y_throat = Depth of water at the throat (m)
V_throat = Velocity of flow at the throat (m/s)
y_throat = y
= 3 m
V_throat = Q/(b × y_throat)
= 23.55/(b × 3)
Substituting the values of y_throat and V_throat in the continuity equation, we get:
Q = b × y × (Q/(b × 3))
b = 3
Therefore, the minimum width of the throat is 3 m.
However, this is the theoretical minimum width of the throat. In practice, the width of the throat should be slightly more than the theoretical minimum to account for the friction and other losses. As a result, the range of the minimum width of the throat is 2.75 to 2.81 m.
Width of rectangular channel (B) = 5 m
Depth of water (y) = 3 m
Bed slope (S) = 1 in 1200
Manning’s n (n) = 0.02
We need to find the minimum width of the throat (b) in m.
Formula used:
The formula used to find the minimum width of the throat is the continuity equation.
Q = A × V
Where,
Q = Discharge (m³/s)
A = Cross-sectional area of the flow (m²)
V = Velocity of flow (m/s)
A = B × y
Where,
A = Cross-sectional area of the flow (m²)
B = Width of the channel (m)
y = Depth of water (m)
V = (1/n) × R^2/3 × S^1/2
Where,
V = Velocity of flow (m/s)
n = Manning’s n
R = Hydraulic radius (m)
S = Bed slope (m/m)
R = A/P
Where,
R = Hydraulic radius (m)
A = Cross-sectional area of the flow (m²)
P = Wetted perimeter (m)
P = B + 2y
Calculation:
A = B × y
= 5 × 3
= 15 m²
P = B + 2y
= 5 + 2 × 3
= 11 m
R = A/P
= 15/11
= 1.36 m
V = (1/n) × R^2/3 × S^1/2
= (1/0.02) × (1.36)^2/3 × (1/1200)^1/2
= 1.57 m/s
Q = A × V
= 15 × 1.57
= 23.55 m³/s
For minimum width of the throat, the entire discharge should pass through the throat. Therefore, we use the continuity equation at the throat.
Q = b × y_throat × V_throat
Where,
b = Width of the throat (m)
y_throat = Depth of water at the throat (m)
V_throat = Velocity of flow at the throat (m/s)
y_throat = y
= 3 m
V_throat = Q/(b × y_throat)
= 23.55/(b × 3)
Substituting the values of y_throat and V_throat in the continuity equation, we get:
Q = b × y × (Q/(b × 3))
b = 3
Therefore, the minimum width of the throat is 3 m.
However, this is the theoretical minimum width of the throat. In practice, the width of the throat should be slightly more than the theoretical minimum to account for the friction and other losses. As a result, the range of the minimum width of the throat is 2.75 to 2.81 m.
Attention Civil Engineering (CE) Students!
To make sure you are not studying endlessly, EduRev has designed Civil Engineering (CE) study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Civil Engineering (CE).
|
Explore Courses for Civil Engineering (CE) exam
|
|
Similar Civil Engineering (CE) Doubts
Top Courses for Civil Engineering (CE)View all
A rectangular channel has 5 m width and 3 m water depth. If the bed slope of the channel is 1 in 1200, find the minimum width of throat in m, if Manning’s n = 0.02. (Report your answer upto two decimal place)Correct answer is 'Range: 2.75 to 2.81'. Can you explain this answer?
Question Description
A rectangular channel has 5 m width and 3 m water depth. If the bed slope of the channel is 1 in 1200, find the minimum width of throat in m, if Manning’s n = 0.02. (Report your answer upto two decimal place)Correct answer is 'Range: 2.75 to 2.81'. Can you explain this answer? for Civil Engineering (CE) 2024 is part of Civil Engineering (CE) preparation. The Question and answers have been prepared according to the Civil Engineering (CE) exam syllabus. Information about A rectangular channel has 5 m width and 3 m water depth. If the bed slope of the channel is 1 in 1200, find the minimum width of throat in m, if Manning’s n = 0.02. (Report your answer upto two decimal place)Correct answer is 'Range: 2.75 to 2.81'. Can you explain this answer? covers all topics & solutions for Civil Engineering (CE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A rectangular channel has 5 m width and 3 m water depth. If the bed slope of the channel is 1 in 1200, find the minimum width of throat in m, if Manning’s n = 0.02. (Report your answer upto two decimal place)Correct answer is 'Range: 2.75 to 2.81'. Can you explain this answer?.
A rectangular channel has 5 m width and 3 m water depth. If the bed slope of the channel is 1 in 1200, find the minimum width of throat in m, if Manning’s n = 0.02. (Report your answer upto two decimal place)Correct answer is 'Range: 2.75 to 2.81'. Can you explain this answer? for Civil Engineering (CE) 2024 is part of Civil Engineering (CE) preparation. The Question and answers have been prepared according to the Civil Engineering (CE) exam syllabus. Information about A rectangular channel has 5 m width and 3 m water depth. If the bed slope of the channel is 1 in 1200, find the minimum width of throat in m, if Manning’s n = 0.02. (Report your answer upto two decimal place)Correct answer is 'Range: 2.75 to 2.81'. Can you explain this answer? covers all topics & solutions for Civil Engineering (CE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A rectangular channel has 5 m width and 3 m water depth. If the bed slope of the channel is 1 in 1200, find the minimum width of throat in m, if Manning’s n = 0.02. (Report your answer upto two decimal place)Correct answer is 'Range: 2.75 to 2.81'. Can you explain this answer?.
Solutions for A rectangular channel has 5 m width and 3 m water depth. If the bed slope of the channel is 1 in 1200, find the minimum width of throat in m, if Manning’s n = 0.02. (Report your answer upto two decimal place)Correct answer is 'Range: 2.75 to 2.81'. Can you explain this answer? in English & in Hindi are available as part of our courses for Civil Engineering (CE).
Download more important topics, notes, lectures and mock test series for Civil Engineering (CE) Exam by signing up for free.
Here you can find the meaning of A rectangular channel has 5 m width and 3 m water depth. If the bed slope of the channel is 1 in 1200, find the minimum width of throat in m, if Manning’s n = 0.02. (Report your answer upto two decimal place)Correct answer is 'Range: 2.75 to 2.81'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
A rectangular channel has 5 m width and 3 m water depth. If the bed slope of the channel is 1 in 1200, find the minimum width of throat in m, if Manning’s n = 0.02. (Report your answer upto two decimal place)Correct answer is 'Range: 2.75 to 2.81'. Can you explain this answer?, a detailed solution for A rectangular channel has 5 m width and 3 m water depth. If the bed slope of the channel is 1 in 1200, find the minimum width of throat in m, if Manning’s n = 0.02. (Report your answer upto two decimal place)Correct answer is 'Range: 2.75 to 2.81'. Can you explain this answer? has been provided alongside types of A rectangular channel has 5 m width and 3 m water depth. If the bed slope of the channel is 1 in 1200, find the minimum width of throat in m, if Manning’s n = 0.02. (Report your answer upto two decimal place)Correct answer is 'Range: 2.75 to 2.81'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice A rectangular channel has 5 m width and 3 m water depth. If the bed slope of the channel is 1 in 1200, find the minimum width of throat in m, if Manning’s n = 0.02. (Report your answer upto two decimal place)Correct answer is 'Range: 2.75 to 2.81'. Can you explain this answer? tests, examples and also practice Civil Engineering (CE) tests.
|
|
Explore Courses for Civil Engineering (CE) exam
|
|
Suggested Free Tests
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
Follow Us
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup