Siphon applications — a siphon is primarily used for which of the following hydraulic purposes?
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Ato fill up a tank with water at higher level from a lower level
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Bnone of these
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Cto supply water to a town from higher level to lower level
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Dto connect water reservoirs at different levels intervened by a hill
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Eto convert turbulent flow to laminar flow in a conduit
Answer
Correct Answer: to connect water reservoirs at different levels intervened by a hill
Explanation
Introduction / Context:A siphon is a closed conduit shaped to rise above the free surfaces of the reservoirs it connects, allowing flow from a higher reservoir to a lower one even when a ridge (hill) lies between them, provided the summit pressure does not drop below vapor pressure significantly.
Given Data / Assumptions:- Two reservoirs at different elevations with an intervening high point.
- The siphon is initially primed (filled with liquid).
- Atmospheric pressure sustains the liquid column at the summit without cavitation.
Concept / Approach:
Flow occurs due to the net head difference between the reservoirs. The siphon’s summit experiences sub-atmospheric pressure; if the elevation exceeds permissible limits, vaporization can break the siphon. Thus, the classic application is bypassing an obstacle like a hill between reservoirs.
Step-by-Step Solution:
Prime the siphon to remove air.Open the outlet to create flow from the higher to the lower reservoir.Ensure summit elevation and losses do not reduce pressure below vapor pressure.Verification / Alternative check (if short method exists):
Bernoulli analysis between free surfaces demonstrates flow direction and confirms sub-atmospheric summit pressure.
Why Other Options Are Wrong:
Filling a higher tank from a lower by siphon violates energy considerations; ordinary town supply does not require crossing a summit; “none” is incorrect; laminarization is unrelated.
Common Pitfalls (misconceptions, mistakes):
Ignoring priming; placing the summit too high; neglecting air leaks that break siphon action.
Final Answer:
to connect water reservoirs at different levels intervened by a hill