Question: Pick up the incorrect statement from the following?

• 1. The mixture of water and waste products, is called sewage
• 2. The treated sewage effluents, are generally used for irrigating the crops
• 3. The process of collecting, treating and disposing off the sewage, is called sewerage
• 4. The old convergence system was definitely better than water carried sewerage system

Question: Pick up the incorrect statement from the following?

• 1. The process of decomposing the organic matter under controlled anaerobic conditions, is called sludge digestion
• 2. Sludge digestion is carried out in sludge tank
• 3. The gases produced in sludge digestion process, contain 75% carbon dioxide
• 4. The gases produced in sludge digestion process, contain 75% methane

Question: The fire demand of a city may be worked out by _________________?

• 1. Kuichling’s formula
• 2. Freeman formula
• 3. Under Writers formula
• 4. All the above.

Question: The yield of a rapid gravity filter as compared to that of slow sand filter, is__________________?

• 1. 10 times
• 2. 15 times
• 3. 20 times
• 4. 30 times

Question: Sunlight_________________ ?

• 1. helps growth of bacterias
• 2. impedes growth of algae
• 3. increases dissolved oxygen content
• 4. reduces turbidity

Question: Average annual rainfall at any station is the average of annual rainfall over a period of________________?

• 1. 7 years
• 2. 14 years
• 3. 21 years
• 4. 35 years

Question: Surge tanks are used_______________?

• 1. for storage water
• 2. to increase the velocity in a pipeline
• 3. as overflow valves
• 4. to guard against water hammer

Question: Biochemical Oxygen Demand (B.O.D.) of safe drinking water must be________________?

• 1. nil
• 2. 5
• 3. 10
• 4. 15

Question: In distribution pipes, drain valves are provided at_______________?

• 1. lower point
• 2. higher point
• 3. junction points
• 4. any where

Question: Asbestos pipes are ______________?

• 1. light in weight and easy to transport
• 2. highly resistant to corrosion
• 3. high flexible to accommodate deflection upto 12°
• 4. all the above