Which of the following is not a heavy industry ? A. iron B. fertilizer C. paperD. none

Pollutants have adverse effect over_________________? A. BiosphereB. Ecosystem C. Both a & b D. Hydrosphere

The main product of bacterial action is_________________? A. Nox B. NO2 C. N2O3D. NO

The percentage of suspended solid waste in raw water is removed by coagulation is__________________? A. 60 B. 70C. 80 D. 90

Which one of the following makes the bulk of hydrospheres content ? A. oceans B. glaciers & icecaps C. fresh water lakes and ponds D. All have equal distribution

Which substance can be used for disinfecting water ? A. KMnO4 B. Alums C. Ozone D. All

The main pollutant of leather tanneries in the waste water is____________________? A. chromium IIIB. chromium IV C. chromium V D. chromium VI

Newspaper can be recycled again and again how many times ? A. 2 B. 3 C. 4D. 5

In the purification of portable water the coagulant used is_________________? A. alum B. nickel sulphate C. copper sulphate D. barium sulphate

Which statement is wrong ? A. the amount of ozone layer is greater in the region close to the equator B. ozone acts as filter for UV radiations C. in the equatorial region it acts as pollutant D. CFCs play…