Top 250+ Solved Water and Wastewater Engineering MCQ Questions Answer
Q. In areas where rainy season is limited to a few months, the type of sewerage systemrecommended is
a. Combined system
b. Partially separate system
c. Separate system
d. None of these
Q. The rate of accumulation of sludge in septic tanks is recommended as
a. 30 litres/person/year
b. 25 litres/person/year
c. 30 litres/person/month
d. 25 litres/person/month
Q. Dried sewage after treatment is used as
a. Fertilizer
b. Building material
c. Chemical for lowering B.O.D.
d. Base material for paints
Q. For drains up to 15 cumecs, the depth “d” and “B” width are related by
a. d = 0.2
b. d = 0.5 B
c. B = 0.2 d
d. B = 0.5 d
Q. In areas where light rains are uniformly distributed throughout the year, the type of seweragesystem to be adopted is
a. Separate system
b. Combined system
c. Partially combined system
d. None of these
Q. Self-cleansing velocity is
a. Velocity at dry weather flow
b. Velocity of water at flushing
c. Velocity at which no accumulation remains in the drains
d. Velocity of water in a pressure filter
Q. 5 days-biochemical oxygen demand (BOD5) is taken at a temperature of
a. 0°C
b. 15°C
c. 20°C
d. 25°C
Q. A well oxidized sewage contains nitrogen mainly as
a. Nitrates
b. Nitrites
c. Free ammonia
d. None of these
Q. In a sludge tank, the gas mainly produced, is
a. Oxygen
b. Nitrogen
c. Hydrogen
d. Carbon dioxide
Q. If “D” is the diameter of upper circular portion, the overall depth of New Egg shaped sewersection, is
a. 1.250 D
b. 1.350 D
c. 1.425 D
d. 1.625 D
Q. In normal conditions, the period for sludge digestion, is
a. 10 days
b. 20 days
c. 30 days
d. 60 days
Q. For evaporation and measurement of settable solids, the apparatus used, is
a. A jar
b. A breaker
c. A test tube
d. An Imhoff cone
Q. For design of sewers, percentage of sewage discharge is assumed
a. 65 to 70
b. 70 to 75%
c. 75 to 80%
d. 85%
Q. The grit chambers of sewage treatment plants, are generally cleaned after
a. 2 days
b. 7 days
c. 12 days
d. 14 days