ENVIRONMENTAL POLLUTION & CONTROL MCQS 22

ENVIRONMENTAL POLLUTION & CONTROL  MCQS 22

1. The ratio of oxygen available to the oxygen required for stabilisation of sewage is called the
(A) Bacterial stability factor
(B) Relative stability
(C) Biological oxygen demand (BOD)
(D) Oxygen ion concentration
Answer: Option B

2. Irradiation of water by ultraviolet light of suitable wavelength is commonly used for disinfection of water in
(A) Food industry
(B) Municipal sewage treatment
(C) Petroleum refinery
(D) Iron & steel plant
Answer: Option A

3. Ozone level is generally found to be depleted in India in the month of
(A) February
(B) July
(C) April
(D) December
Answer: Option D

4. Persons working in cement plants and limestone quarries are more prone to disease like
(A) Cancer
(B) Asthma
(C) Silicosis
(D) Fluorosis (bone disease)
Answer: Option C

5. Thermal pollution due to excessive heat & temperature in the working place causes
(A) Reduction in working efficiency of manpower
(B) Fatigue
(C) High breathing rate
(D) All (A), (B) & (C)
Answer: Option D

6. Presence of soluble organics in polluted water causes
(A) Undesirable plants growth
(B) Depletion of oxygen
(C) Fire hazards
(D) Explosion hazards
Answer: Option B

7. Replenishment of dissolved oxygen in water stream polluted with industrial waste occurs by
(A) Natural aeration of water stream
(B) Photosynthetic action of algae
(C) Both (A) & (B)
(D) Neither (A) nor (B)
Answer: Option C

8. Presence of iron and manganese in water causes
(A) Reduction in its dissolved oxygen content
(B) Discoloration of bathroom fixtures
(C) Temporary hardness
(D) None of these
Answer: Option B

9. The main industrial source of emission of hydrogen sulphide air pollutant is
(A) Petroleum refineries
(B) Coal based thermal power plants
(C) Pulp and paper plant
(D) Metallurgical roasting & smelting plant
Answer: Option B

10. TLV of mercury in potable (drinking) water is about __________ ppm.
(A) 0.001
(B) 0.1
(C) 1
(D) 5
Answer: Option A