Multiple Choice Questions and Answers (MCQ) on Environmental Engineering

01. What is the major constituents of waste/polluted water discharged from textile, pulp & paper, tanning, distillery, dairy and meat packing industries?

(A) Radioactive substances
(B) Natural organic products
(C) Inorganic pollutants
(D) None of these

Answer: Option B

02. Coal mines drainage waste water (acidic in nature) results from the earth’s water percolating through the voids created in coal bed during mining. This polluted water which either drains out naturally to water courses or are removed before starting the mining is

(A) Neutralised by alkali treatment
(B) Left as such without any treatment
(C) Diluted with fresh water to reduce its acidity
(D) None of these

Answer: Option A

03. If carbon monoxide content in atmospheric air exceeds __________ ppm, death is bound to occur.

(A) 50
(B) 500
(C) 1000
(D) 3000 (i.e. 0.3%)

Answer: Option D

04. Ringelmann chart is used for the measurement of the

(A) Combustibles present in automobile exhaust
(B) Smoke density from a chimney
(C) Exhaust gas density
(D) Flue gas temperature

Answer: Option B

05. The permissible color for domestic water supply is __________ ppm.

(A) 1
(B) 20
(C) 100
(D) 1000

Answer: Option B

06. Presence of non-biodegradable substances, like alkyl benzene sulphonate (ABS) from the detergents in polluted water stream causes

(A) Fire hazards
(B) Explosion hazards
(C) Persistent foam
(D) Depletion of dissolved oxygen

Answer: Option C

07. Out of the following, TLV of __________ is the minimum (about 0.02 ppm).

(A) Phosgene
(B) Bromine
(C) MIC (Methyl isocyanate)
(D) Ozone

Answer: Option C

08. Smog is not formed due to the presence of __________ in the atmosphere.

(A) SO2
(B) NOx
(C) CO2
(D) Any of these

Answer: Option C

09. Average human body contains about __________ percent water by weight.

(A) 20
(B) 40
(C) 70
(D) 85

Answer: Option C

10. There are thirteen metals which are treated as pollutants. Which of the following metals is not a pollutant?

(A) Mercury
(B) Arsenic
(C) Aluminium
(D) Lead

Answer: Option C

11. Arsenic pollutant is not generated in __________industries.

(A) Tanneries
(B) Glass & ceramic
(C) Beverages
(D) Any of these

Answer: Option C

12. Pick out the wrong statement.

(A) The concentric layer in atmosphere which contains about 70% of the total mass of atmosphere and characterised by a steady decrease in temperature is called stratosphere
(B) Stratosphere is rich in ozone and is located just above the troposphere
(C) Troposphere is a turbulent dusty zone containing much of water vapor and clouds
(D) The earth’s atmosphere is an envelope of gases extending upto a height of about 200 kms

Answer: Option A

13. The pH value of oxidised sewage is about

(A) 1.8
(B) 6.2
(C) 7.3
(D) 13.4

Answer: Option C

14. On prolonged exposure to high concentration of carbon monoxide (> 5000 ppm), man dies because

(A) Of clotting of blood
(B) Of jamming of respiratory tract
(C) It forms carboxyhemoglobin by combining with haemoglobin of blood, thereby making it incapable of absorbing oxygen
(D) It forms CO2 by combining with oxygen present in the blood

Answer: Option C

15. Growth of __________ is promoted by the presence of manganese in water.

(A) Files
(B) Algae
(C) Micro-organisms
(D) Mosquitoes

Answer: Option C

16. Presence of nitrogen in high concentration in contaminated air reduces partial pressure of oxygen in lungs, thereby causing asphyxia (suffocation) leading to death from oxygen deficiency. Concentration of N2 in contaminated air at which it acts as a natural asphyxiate is ≥ __________ percent.

(A) 84
(B) 88
(C) 80
(D) 92

Answer: Option A

17. In water treatment plant, zeolite process is used to remove the __________ of water.

(A) Acidity
(B) Alkalinity
(C) Hardness
(D) Iron & zinc

Answer: Option C

18. Radioactive solid nuclear wastes are disposed off by

(A) High temperature incineration
(B) Pathological incineration
(C) Pyrolysis
(D) Underground burial in concrete containers

Answer: Option D

19. Disinfection of water is done to remove

(A) Color
(B) Bad taste
(C) Foul odour
(D) Bacteria

Answer: Option D

20. Which of the following is an adsorbent used for the removal of SO2 from gas/air?

(A) Bog iron
(B) Limestone powder or alkalised alumina
(C) Silica gel
(D) Active carbon

Answer: Option B

21. Noise level audible to audience sitting in the 5th row from the stage during a large orchestra show corresponds to about __________ decibels.

(A) 105
(B) 135
(C) 160
(D) 185

Answer: Option B

22. ‘Safe limit’ called Threshold Limit Value (TLV) of carbon monoxide in atmospheric air is < 50 ppm. The main source of carbon monoxide pollutant in air is the

(A) Industrial chimney exhaust
(B) Automobiles exhaust
(C) Photochemical reaction in polluted atmosphere
(D) Burning of domestic fuel

Answer: Option B

23. The average thickness of ozone layer in stratosphere is about __________ dobson unit (DU).

(A) 20
(B) 230
(C) 750
(D) 1500

Answer: Option B

24. __________ plant emits large amount of SO2 as an air pollutant.

(A) Nitric acid
(B) Sulphuric acid
(C) Chlor alkali
(D) Iron & steel

Answer: Option B

25. CFC (chloro fluoro carbon) is very highly reactive in causing depletion of ozone layer in the atmosphere. Each atom of chlorine liberated from CFC is capable of decomposing __________ molecules of ozone.

(A) 102
(B) 105
(C) 109
(D) 1015

Answer: Option B