Environmental Engineering

11.5-200 μm size particles are called

  1. Colloids or aerosols
  2. Powder
  3. Dust
  4. Smoke
Correct answer: (A)
Colloids or aerosols

12.80% less than 200 mesh size particles are called

  1. Smoke
  2. Powder
  3. Grit
  4. Aggregates
Correct answer: (B)

13.A 'body' which allows the short wavelength incoming solar radiation to enter in, but does not allow long wave length outgoing infra red radiation to escape out is called the

  1. Global warming
  2. Green house
  3. Atmospheric effect
  4. Ionosphere
Correct answer: (B)
Green house

14.A considerable part of the harmful ultraviolet radiation of the sum does not reach the earth surface, because of the fact that, there is a layer of _________ high above earth's atmosphere, which absorbs it.

  1. Hydrogen
  2. Carbon dioxide
  3. Ozone
  4. None of these
Correct answer: (C)

15.A gas is termed as non-toxic, if its maximum permissible concentration (TLV) ranges from _________ ppm.

  1. 1000 to 2000
  2. 3000 to 6000
  3. 6000 to 9000
  4. 10000 to 100000
Correct answer: (D)
10000 to 100000

16.A man exposed to excessive noise level in the working environment may suffer from

  1. Hearing loss
  2. Rupture of ear drum
  3. Nervousness&fatigue
  4. All (A), (B)&(C)
Correct answer: (D)
All (A), (B)&(C)

17.A masonry structure built below ground level, where biochemical reaction takes place due to anaerobic bacteria is called

  1. Cesspool
  2. Lagoon
  3. Skimming mill
  4. Septic tank
Correct answer: (D)
Septic tank

18.A shallow pond in which the sewage is retained and biologically treated is called

  1. Oxidation
  2. Imhoff tank
  3. Lagoon
  4. Skimming tank
Correct answer: (A)

19.A standard test for determination of hardness in water is termed as _________ test.

  1. EDTA
  2. Electometric
  3. Total count
  4. Presumptive
Correct answer: (A)

20.Acute danger to human life (i.e. death) exists, if the concentration of CO2 in atmospheric air exceeds _________ percent (by volume).

  1. 1
  2. 3
  3. 7
  4. 20
Correct answer: (D)
Page 2 of 43