# Civil Engineering - Hydraulics - Discussion

### Discussion :: Hydraulics - Section 1 (Q.No.4)

4.

The maximum vacuum created at the summit of a syphon is

 [A]. 2.7 m of water [B]. 7.4 m of water [C]. 5.5 m of water [D]. none.

Explanation:

No answer description available for this question.

 Knreddy said: (Feb 25, 2015) Summit of syphon means what?

 Gopi said: (Mar 29, 2015) It is the highest point hill is called summit syphon is bend pipe. It is flowing of water to higher elevation to lower elevation.

 Pratik said: (Aug 27, 2015) The answer should be A because vapour pressure head of water is 2.7 m of water.

 Md Sharique said: (Sep 16, 2015) It is the highest point hill is called summit syphon is bend pipe. It is flowing of water to higher elevation to lower elevation.

 Ravi said: (Oct 19, 2016) @Pratik. Your answer will satisfy the Condition of cavities. B answer is right.

 Krishna said: (Oct 20, 2016) I think 7.6 m of water.

 Pravin Kamble said: (Nov 14, 2016) According to me, 2.7 is the correct answer.

 Suryan said: (Nov 25, 2016) It should be 7.8m water.

 Vivek said: (Mar 9, 2017) It should be less than 7.8 because if it goes above 7.8 dissolved gases in the liquid will come out and accumulated at a summit and will stop flow of water.

 Abhishek Anand said: (Apr 23, 2017) The pressure at summit point will be less than the atmospheric pressure . Theoretically, the pressure at summit may be reduced to 10.3 m of water but in actual practice, this pressure is only 7.6 m of water or 10.3-7.6= 2.7m of water absolute. if the pressure at summit become less than 2.1m of water absolute, the dissolved air and other gases would come out from water and collect at the summit.the flow of water will be obstructed.

 Iwansh said: (May 11, 2017) 10.3m of H2O = 76Cm of hg. 1 m of H2O = 7.378. So the answer is B.

 Syam said: (Jul 26, 2017) Here it is 7.4m of Vaccum pressure and 2.5m of absolute pressure for water.

 Sunny said: (May 8, 2018) 10.3m of H2O = 76Cm of hg. 1 m of H2O = 7.378. So, the answer is B.

 Anju Singh Patel said: (Jun 13, 2018) 1mof h2o 76/10.3 = 7.4.

 Pratik said: (Jul 11, 2018) It is 2.3 to 2.7.

 Archana said: (Sep 12, 2018) It is -7.6 or 10.3 - 7.6 = 2.7m of water.

 Vivek Bahra said: (Oct 17, 2018) For water absolute = 2.5. For water vacuum = 7.8. Here it is asked for vacuum. Hence the answer is 7.8.

 Raz said: (Aug 9, 2019) 7.4m is 100% correct.

 Chandan said: (Aug 20, 2019) It is also less then the atmospheric pressure.

 Sagar Shingne said: (Nov 5, 2019) Absolute 2.5. Vacuum 7.8.

 Soumya said: (May 17, 2020) How to calculate maximum vacuum height?

 Laxmi Shah said: (May 26, 2020) The minimum vacuum created at the summit of a syphon.

 Shivanshu said: (Jun 29, 2020) For vacuum, it will be 7.8.

 Sunil said: (Nov 23, 2020) The pressure is only -7.6m of water or 10.3-7.6= 2.7 m of water absolute. p vacuum = p atm - p absolute. So maximum vacuum = 10.3-2.7 = 7.6 m.

 Jibin said: (Jun 11, 2021) The pressure at the summit is always less than atmospheric pressure. So, the highest point according to options is 7.4 that is less than 10.33, so the answer B is correct.