Question

Download Solution PDF

Two reservoirs connected by tow pipe lines in parallel of the same diameter D and length. It is proposed to replace the two pipe lines by a single pipeline of the same length without affecting the total discharge and loss of head due to friction. The diameter of the equivalent pipe De terms of the diameter of the existing pipe line,  is:

This question was previously asked in
ESE Mechanical 2016 Paper 1: Official Paper
Attempt in App
View all UPSC IES Papers >
  1. 4.0

Answer (Detailed Solution Below)

Option 4 :
Free Tests
View all Free tests >
Free
ST 1: UPSC ESE (IES) Civil - Building Materials
20 Qs. 40 Marks 24 Mins
Start Now

Detailed Solution

Download Solution PDF

Concept:

When two pipes are replaced by the equivalent pipe in the case of parallel pipes then head loss across the pipes are same

As the head loss is equal in both cases,

And the discharge through the equivalent pipe is equal to the sum of discharge through the individual pipes

Qeq = Q1 + Q2

we have,

Aeq × Veq = 2 A × V

Since

and

Now,

Download Solution PDF
Latest UPSC IES Updates

Last updated on Jun 23, 2025

-> UPSC ESE result 2025 has been released. Candidates can download the ESE prelims result PDF from here.

->  UPSC ESE admit card 2025 for the prelims exam has been released. 

-> The UPSC IES Prelims 2025 will be held on 8th June 2025.

-> The selection process includes a Prelims and a Mains Examination, followed by a Personality Test/Interview.

-> Candidates should attempt the UPSC IES mock tests to increase their efficiency. The UPSC IES previous year papers can be downloaded here.

Exams Tests Super Practice

More Equivalent Pipe Questions

Q1.A compound pipeline consists of two pieces of identical pipes. The equivalent length of the same diameter and the same friction factor for this compound pipeline is L1 when the pipes are connected in series and is L2 when the pipes are connected in parallel. Determine the ratio of equivalent lengths, that is, L1 to L2.
Q2.Dupit’s equation is expressed for series-connected pipes as: (where L1, L2, and L3 are lengths of pipe 1, 2 and 3, d1, d2, d3 are diameter of pipe 1, 2 and 3, L is equivalent length of pipe are D is equivalent diameter of pipe)
Q3.Which of the following methods of analysis of water distribution system is most suitable for long and narrow pipe system?
Q4.Two pipes of length 800m, 1000m, and diameter 500 mm and 600 mm respectively are connected in series. If these pipes are to be replaced by a single pipe of length 1800m, then find its diameter?
Q5.A pipeline of 300 mm diameter carrying water at an average velocity of 5 metre/sec branches into two pipes of 150 mm and 200 diameter. The total flow rate of discharge of water in the system is
Q6.Two reservoirs connected by tow pipe lines in parallel of the same diameter D and length. It is proposed to replace the two pipe lines by a single pipeline of the same length without affecting the total discharge and loss of head due to friction. The diameter of the equivalent pipe De terms of the diameter of the existing pipe line, \(\frac{{{D_e}}}{D},\) is:
Q7.If l1, l2, l3 etc. be the lengths and d1, d2, d3 etc. be the diameters of the parts of a compound pipe, then length L and diameter D of a uniform equivalent pipe will be related as under (A) \(\frac{L}{D} = \frac{{{l_1}}}{{{d_1}}} + \frac{{{l_2}}}{{{d_2}}} + \frac{{{l_3}}}{{{d_3}}} + \ldots \) (B) \(\frac{L}{{{D^2}}} = \frac{{{l_1}}}{{d_1^2}} + \frac{{{l_2}}}{{d_2^2}} + \frac{{{l_3}}}{{d_3^2}} + \ldots \) (C) \(\frac{L}{{{D^3}}} = \frac{{{l_1}}}{{d_1^3}} + \frac{{{l_2}}}{{d_2^3}} + \frac{{{l_3}}}{{d_3^3}} + \ldots \) (D) \(\frac{L}{{{D^5}}} = \frac{{{l_1}}}{{d_1^5}} + \frac{{{l_2}}}{{d_2^5}} + \frac{{{l_3}}}{{d_3^5}} + \ldots \)
Q8.In series-pipe applications
Q9.Three identical pipes of lengh L, diameter d and friction factor f are connected in parallel between two reservoirs. What is the size of pipe of length L and of the same friction factor f equivalent to the above pipe?
Q10.A compound pipeline consists of two pieces of identical pipes. The equivalent length of same diameter and same friction factor, for the compound pipeline is L1 when pipes are connected in series, and is L2 when connected is parallel. What is the ratio of equivalent lengths L1 to L2?

More Flow Through Pipes Questions

Q1.Which of the following statements about manometric head is correct?
Q2.If a square pipe of side 60 cm, carries a discharge of 3 m/sec, the velocity of flow(m/sec) in the pipe is: 
Q3.The relation of friction loss factor, f = \(\rm \frac{0.3164}{(Re)^{0.25}}\) is correct for which of the following flow?
Q4.Which of the following statements is INCORRECT about the friction factor of Darcy's equation? 
Q5.Total gradient line (or total energy line) is parallel to hydraulic gradient line with a vertical distance of _________. (The symbols have their usual meanings.) 
Q6.A compound pipeline consists of two pieces of identical pipes. The equivalent length of the same diameter and the same friction factor for this compound pipeline is L1 when the pipes are connected in series and is L2 when the pipes are connected in parallel. Determine the ratio of equivalent lengths, that is, L1 to L2.
Q7.Which of the following is NOT the remedial measure to prevent water hammer through pipes?
Q8.Which of the following is NOT a reason for minor head loss in pipe flow?
Q9.A Moody diagram represents ______ as a function of Reynolds number, in a pipe flow. 
Q10.When pipes of different diameters are connected in series from end to end to form a pipe line, the total head loss developed is equal to _______
Suggested Test Series
View All >
UPSC ESE (IES) Civil Mock Test Series
116 Total Tests with 1 Free Tests
Start Free Test
UPSC ESE (IES) Prelims Paper 1 Mock Test Series
54 Total Tests with   1 Free Tests
Start Free Test

UPSC IES Important Links

ResultHall TicketEligibilitySalary and Job ProfileExam PatternECE Syllabus

More Fluid Mechanics Questions

Q1.Which of the following best defines vapour pressure in a liquid?
Q2.Priming of a pump refers to:
Q3.How does the volute shape in a single volute pump casing affect performance?
Q4.One challenge associated with double volute casings is:
Q5.Manometric head is defined as:
Q6.Compared to axial flow pumps, radial flow pumps typically:
Q7.How does atmospheric pressure influence gauge pressure measurements?
Q8.Fluid pressure is defined as:
Q9.A pitot tube is primarily used to measure:
Q10.A pump discharges water with a manometric head of 20 m. If the density of water is 1000 kg/m3 and gravity is 9.81 m/s2 , what is the approximate pressure increase provided by the pump?
Testbook Edu Solutions Pvt. Ltd.
1st & 2nd Floor, Zion Building,
Plot No. 273, Sector 10, Kharghar,
Navi Mumbai - 410210
support@testbook.com
Toll Free:1800 833 0800
Office Hours: 10 AM to 7 PM (all 7 days)
Company
About usCareers We are hiringTeach Online on TestbookPartnersMediaSitemap
Products
Test SeriesTestbook PassOnline CoursesOnline VideosPracticeBlogRefer & EarnBooks
Copyright © 2014-2022 Testbook Edu Solutions Pvt. Ltd.: All rights reserved
User PolicyTermsPrivacy
Hot Links： teen patti rummy teen patti gold downloadable content teen patti - 3patti cards game downloadable content teen patti rummy 51 bonus