Hydrostatics: Under which condition will a siphon fail to operate? Assume a standard siphon transferring liquid from a higher container to a lower one through a tube arching over the rim. Choose the correct option.
IIT JEE
Physics
Difficulty: Medium
Choose an option
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AIf the discharge end is lower than the source surface
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BIf the tube contains no air bubbles
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CIn a vacuum, where atmospheric pressure is absent
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DWhen the receiving vessel is below the source
Answer
Correct Answer: In a vacuum, where atmospheric pressure is absent
Explanation
ConceptA siphon works because a continuous liquid column is sustained, with atmospheric pressure plus gravity maintaining flow from higher to lower level. Classic analysis uses atmospheric pressure to start and sustain the column over the crest.
ReasoningIn vacuum, the pressure support is absent and vapor cavities form, breaking the column; practical siphons fail. (Additionally, if both levels are the same or the crest exceeds barometric height for the liquid, siphoning fails.)
Final AnswerIn a vacuum, where atmospheric pressure is absent