In a residential colony, sewers of diameters 100 mm, 150 mm and 225 mm were laid with a gradient 1 in 120. Which portion of the sewage system does not choke in due course of time?

In a residential colony, sewers of diameters 100 mm, 150 mm and 225 mm were laid with a gradient 1 in 120. Which portion of the sewage system does not choke in due course of time?

A. 100 mm dia.
B. 150 mm dia.
C. 225 mm dia.
D. All of these

If D is the diameter of a circular sewer and D’ is the top horizontal diameter of an equivalent egg shaped section, the relationship which holds good, is_______________?

If D is the diameter of a circular sewer and D’ is the top horizontal diameter of an equivalent egg shaped section, the relationship which holds good, is_______________?

A. D’ = 0.64 D
B. D’ = 0.74 D
C. D’ = 0.84 D
D. D’ = 0.94 D

Nitrogen cycle of sewage, is____________________?

Nitrogen cycle of sewage, is____________________?

A. Liberation of ammonia-formation of nitrites-formation of nitrates-liberation of nitrogen
B. Liberation of nitrogen-liberation of ammonia-formation of nitrites- formation of nitrates
C. Liberation of nitrogen-formation of nitrates-formation of nitrites-liberation of ammonia
D. Formation of nitrates-formation of nitrites-liberation of nitrates-liberation of nitrates