A. Methane gas
B. Hydrogen sulphide
C. Carbondioxide gas
D. Diesel vapours
Related Mcqs:
- If a paper moistened with lead acetate for five minutes when placed in manhole turns black. The sewer certainly contains__________________?
A. Hydrogen sulphide
B. Carbon dioxide
C. Methane
D. Oxygen - If the flame of a miner’s safety lamp in a manhole extinguishes within 5 minutes, the sewer certainly contains_______________?
A. Hydrogen sulphide
B. Carbon dioxide
C. Methane
D. Oxygen - A safety lamp when inserted in the upper portion of a manhole causes flames. It indicates the presence of______________?
A. Carbondioxide gas
B. Hydrogen sulphide gas
C. Methane gas
D. Petrol vapours - If the flame of a miner’s safety lamp in the upper layers of the sewer forms an explosive, the sewer certainly contains_______________?
A. Hydrogen sulphide
B. Carbon dioxide
C. Methane
D. Oxygen - If the discharge of a sewer running half is 628 1.p.s., i = 0.001, and n = 0.010, the diameter of the sewer, is__________________?
A. 1.39 m
B. 1.49 m
C. 1.59 m
D. 1.69 m - The spacing of man holes along a straight portion of a sewer is 300 m, the diameter of the sewer may be__________________?
A. 0.9 cm
B. 1.2 m
C. 1.5 m
D. > 1.5 m - The width of a rectangular sewer is twice its depth while discharging 1.5 m/sec. The width of the sewer is______________?
A. 0.68 m
B. 0.88 m
C. 1.36 m
D. 1.76 m - Assertion A.: The minimum self cleansing velocity in the sewer, at least once a day, must be generated. Reason (R): If certain deposition takes place and is not removed, it obstructs free flow and causes further deposition leading to complete blocking of the sewer?
A. Both A and R are true and R is the correct explanation of A
B. Both A and R are true but R is not a correct explanation of A
C. A is true but R is false
D. A is false but R is true - You are asked to design sewer pipes of diameters 0.4 m to 0.9 m at maximum flow, you will assume the sewer flow running at___________________?
A. Full depth
B. Half full
C. Two third full
D. Three fourth full - weight of water, the hydraulic mean depth of the sewer and the bed slope w is the unit of the sewer, then the tractive force exerted by flowing water, is________________________?
A. w r S S
B. w r1/2
C. w r S
D. w r2/3
