Pascal-second is the unit of______________?
(A) pressure
(B) kinematic viscosity
(C) dynamic viscosity
(D) surface tension
An ideal fluid is_______________?
(A) one which obeys Newton’s law of viscosity
(B) frictionless and incompressible
(C) very viscous
(D) frictionless and compressible
The settling velocity of a particle in a sedimentation tank increases if______________?
(A) particle size is decreased
(B) the surface area of tank is increased
(C) the depth of tank is decreased
(D) none of the above
Percentage of bacterial load that can be removed from water by the process of plain sedimentation is about_______________?
(A) 10 to 25
(B) 50
(C) 75
(D) 100
The length of rectangular sedimentation tank should not be more than_______________?
(A) B
(B) 2B
(C) 4B
(D) 8B
The dissolved oxygen level in natural unpolluted waters at normal temperature is found to be of the order of________________?
(A) 1 mg/litre
(B) 10 mg/litre
(C) 100 mg/litre
(D) 1000 mg/litre
If the total hardness of water is greater than its total alkalinity, the carbonate hardness will be equal to________________?
(A) total alkalinity
(B) total hardness
(C) total hardness – total alkalinity
(D) non carbonate hardness
Residual chlorine in water is determined by________________?
(A) starch iodide method
(B) orthotolidine method
(C) both (A) and (B)
(D) none of the above
Turbidity is measured on_______________?
(A) standard silica scale
(B) standard cobalt scale
(C) standard platinum scale
(D) platinum cobalt scale
The maximum permissible limit for flouride in drinking water is______________?
(A) 0.1 mg/litre
(B) 1.5 mg/litre
(C) 5 mg/litre
(D) 10 mg/litre