![Two water reservoirs are connected by a siphon (running full) of total length 5000 m and diameter of 0.10 m, as shown below (figure not drawn to scale)](https://www.gkseries.com/blog/wp-content/uploads/2023/07/Two-water-reservoirs-are-connected-by-a-siphon-running-full-of-total-length-5000-m-and-diameter-of-0.10-m-as-shown-below-figure-not-drawn-to-scale.jpg)
Q. Two water reservoirs are connected by a siphon (running full) of total length 5000 m and diameter of 0.10 m, as shown below (figure not drawn to scale).
![](https://www.gkseries.com/blog/wp-content/uploads/2023/07/Screenshot-434.png)
The inlet leg length of the siphon to its summit is 2000 m. The difference in the water surface levels of the two reservoirs is 5 m. Assume the permissible minimum absolute pressure at the summit of siphon to be 2.5 m of water when running full. Given: friction factor f = 0.02 throughout, atmospheric pressure = 10.3 m of water, and acceleration due to gravity g = 9.81 m/s2. Considering only major loss using Darcy-Weisbach equation, the maximum height of the summit of siphon from the water level of upper reservoir, h (in m, round off to 1 decimalplace) is
Solution:
Applying Bernoulli’s equation at A & B:
![](https://www.gkseries.com/blog/wp-content/uploads/2023/07/Screenshot-435.png)