Q96
The effect of increasing diameter of sewer on the self cleansing velocity is
A.
To decrease it
B.
To increase it
C.
Fluctuating
D.
Nil
AnswerAnswer: Option D
Solution
Answer: Option D
Solution:
Self-cleansing velocity is the minimum velocity required to prevent the deposition of solids and keep the sewer clean. It depends on the diameter of the grain (particle size) rather than the diameter of the sewer.
The self-cleansing velocity in a sewer is typically given by the formula:
v = k * sqrt(g * d * (G - 1) / f)
Where,
v = Self-cleansing velocity
k = Sediment coefficient
g = Acceleration due to gravity
d = Particle diameter
G = Specific gravity of the particle
f = Friction factor
From this equation, it is evident that self-cleansing velocity is independent of the sewer diameter.
Thus, increasing the sewer diameter has no effect on the self-cleansing velocity.