Question

Given below are two statements
Statement I: Culverts are only used when the irrigation channel is at a higher elevation than the obstruction to be crossed.
Statement II: Siphons are used when the channel level is almost same or higher than the obstruction.
In the light of the above statements, choose the correct answer from the options given below:

• A. Both Statement I and Statement II are true
• B. Both Statement I and Statement II are false
• C. Statement I is true but Statement II is false
• D. Statement I is false but Statement II is true

Hint:

Cross drainage structures:
- Culvert: Canal passes over drain/road (same or higher level).
- Syphon: Canal passes under drain/road (lower level).
- Inverted syphon: Canal passes under a depression.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
This question tests knowledge of cross drainage structures.

Step 2: Detailed Explanation:
Statement I:
Culverts are used when the canal passes over a drain or road.
The canal is at a higher elevation, and the obstruction (road/drain) is at a lower level.
But culverts are also used when the canal is at the same level as the obstruction.
The statement says "only used when the irrigation channel is at a higher elevation" which is not entirely correct.
Culverts are used when the canal crosses a road or drain, regardless of elevation difference.
This statement is false.
Statement II:
Siphons are used when the channel level is almost the same or higher than the obstruction.
Siphons work on the principle of pressure difference to convey water under an obstruction.
This statement is true.

Step 3: Final Answer:
Thus, Statement I is false but Statement II is true.
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