Engineering Questions with Answers - Multiple Choice Questions
Environmental Engineering MCQ’s – Forces and Loads on Sewer
The magnitude of hoop stress on sewer is given __________
Explanation: The magnitude of hoop stress on sewer is given by PD/2t where, P is the internal pressure, D is the diameter of sewer and t is the thickness of the shell.
In order to reduce temperature stress ______________ joints are provided.
c) Bell and spigot
Explanation: In order to reduce temperature stress, expansion joints are provided at intervals of 20m to 30m.
The expression for the temperature stress is given by __________
Explanation: The expression for the temperature stress is given by EPαt where, EP is the modulus of elasticity of pipe, α is the coefficient of thermal expansion and ‘t’ is the change in temperature.
The type of backfill is saturated clay. What is its unit weight?
Explanation: When the type of backfill is saturated clay, then its unit weight is 2080kg/m3.
Which of the following has the minimum unit weight?
a) Dry sand
b) Wet sand
c) Damp clay
d) Ordinary sand
Explanation: The unit weight of wet sand, damp clay, ordinary sand and dry sand are 1920kg/m3, 1920kg/m3, 1840kg/m3 and 1600kg/m3 respectively.
The type of soil is loose dry sand. What is the coefficient of cohesion of the soil?
Explanation: Loose dry sand is a cohesionless soil. So, the value of the coefficient of cohesion is 0.
Which of the following order is correct regarding coefficient of cohesion?
a) Hard clay < Dense sand > Medium clay > Soft clay
b) Hard clay > Dense sand > Medium clay > Soft clay
c) Medium clay > Dense sand > Hard clay > Soft clay
d) Dense sand > Medium clay > Hard clay > Soft clay
Explanation: The coefficient of cohesion of Hard clay, Dense sand, Medium clay and Soft clay are 4700kg/m2, 1400kg/m2, 1200kg/m2 and 200kg/m2 respectively.
How many types of underground sewer are there on the basis of construction conditions?
Explanation: Depending upon the type of the construction conditions, underground sewers are of 3 types, namely Trench ditch condition, Embankment condition and Tunnel condition.
______ condition exists when the sewer is laid at a depth between 9m to 12m.
a) Trench ditch
Explanation: Tunnel condition exists when the sewer is laid at a depth between 9m to 12m. This process is done by jacking or by tunneling.
Negative projecting condition is a type of ______ condition.
a) Trench ditch
Explanation: Negative projecting condition exists when the trench is narrower with respect to the size of the pipe and shallow with respect to the depth of cover.