Kingdom of Saudi Arabia
Ministry of Higher Education
Majmaah University
College of Engineering
Civil Engineering Department
Exam Information
Second Midterm Exam
Course code:
CE 362
Instructor:
Section number:
Exam time:
Number of pages:
Zia ur Rehman
571
Exam date:
From:
11:00 a m
6
Total score:
Student’s Information
Name:
Course Title:
Water Supply and
Sewage Engineering
To:
04/12/2014
12:30 pm
20 points
ID:
Exam Instructions:
 Read the questions carefully and several times. Writing clearly will make it possible to
assess your answers correctly.
 Any form of cheating, intention to cheating, or disruption of the exam will subject you to
a disciplinary action as specified by the university’s regulations.
 Carrying or using the mobile phone during the exam is not allowed. Using the phone
during the exam will carry a disciplinary action.
 The calculator is only permitted by the exam supervisor.
 No student can leave the exam room during the first half hour of the exam. Any student
coming after the first half hour of the exam will not be permitted to enter the exam.
 A student leaving the exam, even for legitimate reasons, may not be given a makeup
exam.
Points Earned:
Question
Score
Question
Score
1 (4)
3 (4)
2 (4)
4 (4)
5 (4)
Total score of the exam:
Dear student, we encourage you to answer the exam the best you can and we wish you all
success.
1
Question 1: Enlist the number of materials used for sewer construction and explain the
advantage and disadvantage of any one of them.
2
Question 2: Determine designed discharge for a separate and combined system serving
population density 500 person/hectare with rate of water supply of 135 LPCD. The catchment
area is 100 hectares and the average coefficient of runoff is 0.65. The time of concentration for
the design rainfall is 25 min and the relation between intensity of rainfall and duration is
I = 1000/ (t + 20) mm/hr.
3
Question 3: Calculate quantity of water supplied from the water works in LPCD if the Net
quantity of sewage is 8x106 liter per day (LPD) under following conditions:
 City population is 48000 population
 1.5x106 liter per day addition due to unaccounted private water supplies.
 8% of municipal water supply Addition due to infiltration
 5% of municipal water supply water losses
 15% of municipal water supply not entering in the sewerage system
4
Question 4:
Write advantages and disadvantages of combined sewer system.
5
Question 5: Calculate the diameter of the organic and inorganic particles having self-cleaning
velocity is 0.45 m/s.
K= constant, for clean inorganic solids = 0.04 and for organic solids = 0.06
f' = Darcy Weisbach friction factor (for sewers = 0.03)
Ss = Specific gravity of sediments = 2.65 for inorganic solid and 1.20 for organic solids
g = gravity acceleration
6