The gas which may cause explosion in sewers, is_________________?
(A) Carbondioxide
(B) Methane
(C) Ammonia
(D) Carbon monoxide
The discharge per unit plan area of a sedimentation tank, is generally called________________?
(A) Over flow rate
(B) Surface loading
(C) Over flow velocity
(D) All the above
The settling velocity of the particles larger than 0.06 mm in a settling tank of depth 2.4 is 0.33 m per sec. The detention period recommended for the tank, is____________________?
(A) 30 minutes
(B) 1 hour
(C) 1 hour and 30 minutes
(D) 2 hours
Pick up the incorrect statement from the following for allowing workers to enter sewers_______________?
(A) The particular manhole and one manhole on upstream and one manhole on downstream should remain open for 30 minutes
(B) Proper tests for the presence of poisonous gases must be carried out
(C) The men entering the manhole should be advised to smoke in the sewer
(D) Warning signals should be erected
To prevent settling down of sewage both at the bottom and on the sides of a large sewer, self-cleaning velocity recommended for Indian conditions, is_________________?
(A) 0.50 m/sec
(B) 0.60 m/sec
(C) 0.70 m/sec
(D) 0.75 m/sec
The normal values of over flow rates for sedimentation tanks using coagulant, ranges between__________________?
(A) 25,000 to 35,000 litres/sqm/day
(B) 40,000 to 50,000 litres/sqm/day
(C) 50,000 to 60,000 litres/sqm/day
(D) 80,000 to 100,000 litres/sqm/day
At the junction of sewers___________________?
(A) Top of smaller sewer is kept lower
(B) Top of larger sewer is kept lower
(C) Tops of both the sewers are at the same level
(D) None of these
The property of a fluid which enables it to resist tensile stress is known as________________?
(A) compressibility
(B) surface tension
(C) cohesion
(D) adhesion
(D) viscosity.
Property of a fluid by which its own molecules are attracted is called ________________?
(A) adhesion
(B) cohesion
(C) viscosity
(D) compressibility
(D) surface tension