Zigya Logo

Chapter Chosen

Environmental Issues

Book Chosen

Biology

Subject Chosen

Biology

Book Store

Download books and chapters from book store.
Currently only available for.
CBSE Gujarat Board Haryana Board

Previous Year Papers

Download the PDF Question Papers Free for off line practice and view the Solutions online.
Currently only available for.
Class 10 Class 12

Which of the following in sewage treatment remove suspended solids?

  • Tertiary treatment

  • Secondary treatment

  • Primary treatment

  • Sludge treatment


C.

Primary treatment


What is the term for the inflammation of cornea due to high absorption of UV-B radiation :
  • myopia
  • snow blindness
  • biomagnification
  • None of the above

B.

snow blindness

Which of the following pollutants is not produced by exhaust of motor vehicles ?
  • CO
  • Hydrocarbon
  • Fly-ash
  • NO

C.

Fly-ash

Ozone depletion will cause :
  • Forest fire
  • Pneumonia
  • Increased incidence of skin cancer
  • None of these

C.

Increased incidence of skin cancer

The meaning of BOD is :
  • Bacterial oxygen demand
  • Biological optimum density
  • Biochemical oxygen demand
  • Bioorganisation decay

C.

Biochemical oxygen demand

In the scrubber in the electrostatic precipitator the gases are passed through :
  • filter
  • lime
  • spray of water
  • both 2 and 3

D.

both 2 and 3