A. Circular septic tanks
B. Rectangular septic tanks
C. Circular Imhoff double tanks with bottom hoppers
D. Circular Imhoff double storey tanks without bottom hoppers 
		A. Circular septic tanks
B. Rectangular septic tanks
C. Circular Imhoff double tanks with bottom hoppers
D. Circular Imhoff double storey tanks without bottom hoppers 
		A. 100 mm dia.
B. 150 mm dia.
C. 225 mm dia.
D. All of these
		A. D’ = 0.64 D
B. D’ = 0.74 D
C. D’ = 0.84 D
D. D’ = 0.94 D
		A. The shape is rectangular
B. Detention period is 2 hours
C. The velocity of flow is restricted to 0.30 m/minute
D. All the above
		A. 3 m
B. 3.5 m
C. 4 m
D. 4.5 m
		A. Weight of the pipe
B. Weight of the back fill
C. Superimposed traffic loads
D. All the above
		A. Ammonia and nitrogen
B. Nitrogen and organic nitrogen
C. Organic nitrogen and ammonia
D. All the above
		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 
		A. 10 cm
B. 15 cm
C. 20 cm
D. 25 cm
		A. The materials separated by screens, is called screenings
B. The screenings are disposed off either by burning or by burial or by dumg
C. The process of burning the screenings, is known as compositing
D. All the above