The rate of BOD exerted at any time is_____________?

A. Directly proportional to bod satisfied
B. Directly proportional to bod remain-ing
C. Inversely proportional to bod satisfied
D. Inversely proportional to bod re-maining

Standard BOD is measured at________________?

A. 20°c – 1day
B. 25°c- 3day
C. 20°c – 5day
D. 30°c- 5day

Sewage treatment units are normally designed for______________?

A. 5-10 years
B. 15-20 years
C. 30-40 years
D. 40-50 years

The pathogens can be killed by_______________?

A. Nitrification
B. Chlorination
C. Oxidation
D. None of the above

The type of sewer which is suitable for both combined and separate system is_____________?

A. Circular sewer
B. Egg shaped sewer
C. Horse-shoe type sewer
D. Semi-elliptical sewer

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

The velocity of flow does not depend on_______________?

A. Grade of sewer
B. Length of sewer
C. Hydraulic mean depth of sewer
D. Roughness of sewer

Most suitable section of sewer in separate sewage system is________________?

A. Rectangular section
B. Circular section
C. Standard form of egg shaped sewer
D. Modified egg shaped section

The minimum and maximum diameters of sewers shall preferably be_________________?

A. 15 cm and 100 cm
B. 15 cm and 300 cm
C. 30 cm and 450 cm
D. 60 cm and 300cm

The design discharge for the separate sewer system shall be taken as_____________?

A. Equal to dry weather flow (dwf)
B. 2xdwf
C. 3 x dwf
D. 6xdwf