Engineering Jobs   »   QUIZ : CIVIL ENGINEERING (07-10-2020)


Quiz: Civil Engineering
Topic: Environmental Engineering

Each question carries 1 mark
Negative marking: 1/4 mark
Time: 10 Minutes

Q1. Water is considered ‘hard’, if its hardness is of the order of
(a) 50 ppm
(b) 100 ppm
(c) 200 ppm
(d) 300 ppm

Q2. Phenolphthalein indicator is used to determine the alkalinity above pH
(a) 8.3
(b) 7.0
(c) 6.5
(d) 4.5

Q3. Methemoglobinemia is caused due to drinking of water having excess of
(a) fluorides
(b) iron
(c) hardness
(d) nitrates

Q4. MPN Index is a measure of which one of the following
(a) B. O. D.
(b) Hardness
(c) D.O. content
(d) Coliform bacteria

Q5. Presence of which one of the following in water is the major cause of depression, paralysis, blindness and/or birth defects?
(a) Cadmium
(b) Chromium
(c) Manganese
(d) Mercury

Q6. In the design of a sedimentation tank the essential factor to be considered is
(a) depth of tank
(b) turbidity of water
(c) concentration of suspended solids in the water
(d) surface loading of tank

Q7. The rapid gravity filters, as compared to slow sand filters, have
(a) much smaller area
(b) more flexibility
(c) faster action
(d) all the above

Q8. Manholes are generally located
(a) at all changes of direction of sewer
(b) at all changes of gradient of sewer
(c) at all junctions of different sewers
(d) All of the above

Q9. BOD_5 represents 5 days-biochemical oxygen demand at a temperature of
(a) 0°C
(b) 20°C
(c) 30°C
(d) None of these

Q10. The ultimate BOD value of a waste
(a) increases with temperature
(b) decreases with temperature
(c) remains the same at all temperatures
(d) doubles with every 10°C rise in temperature


S1. Ans.(c)
Sol. Water with hardness upto 75 ppm are considered soft while those with 200 ppm and above are considered hard.

S2. Ans.(a)
Sol. Phenolphthalein turns water into pink. If pH is more than 8.3 at pH = 8.3, it changes the water from pink to colourless.

S3. Ans.(d)
Sol. Methemoglobinemia or blue baby disease is caused due to nitrate concentration above 45 mg/l in water.

S4. Ans.(d)
Sol. MPN (Most Probable Number) is used to measure total coliform in water sample.

S5. Ans.(b)
Sol. Presence of chromium in water is the major cause of depression, paralysis, blindness and birth defect

S6. Ans.(d)
Sol. Surface loading of tank should be less than the setting velocity of discrete particles for effective sedimentation.

S7. Ans.(d)

S8. Ans.(d)

S9. Ans.(b)
Sol. (BOD)_5 represent 5-days biochemical oxygen demand at a temperature of 20°C.

S10. Ans.(c)
Sol. Ultimate BOD represents the biodegradable organic matter, so it will remain unchanged.

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