Related Questions

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
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
The molecularity and the order of reaction respectively, for the hydrolysis of methyl acetate in presence of acids are
A 2 & 1
B 11 & 2
C 2 & 2
D 1 & 1
A manhole is classified as shallow if its depth is between
A 0.4 to 0.5 m
B 0.5 to 0.7 m
C 0.7 to 0.9 m
D 0.9 to 1.20 m
A manhole is generally provided at each
A Bend
B Junction
C Change of gradient
D All the above
The inspection pit or chamber is a manhole provided in a base drainage system
A At every change of direction
B At every change of gradient
C At every 30 m intervals
D All the above
A drop manhole is provided if
A A sewer drops from a height
B A branch sewer joins the main sewer at higher level
C A lamp is inserted to check obstruction
D None of these
Grey cast iron (used for making underground water pipes and manhole covers) as compared to steel has higher
A Ductility
B Impact strength
C Machinability
D Melting point
TLV of lead for public sewer/waste water is about __________ ppm.
A 1
B 25
C 150
D 650

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