1. Top soil contains-
(a) Humus & soil particles
(b) Humus, living organisms & plants
(c) Humus & living organisms
(d) Humus, living organisms & soil particles
2. The kind of soil water most useful to plants is
(a) Distilled water
(b) Capillary water
(c) Gravitational water
3. Wind causes weathering of rocks through
(b) Chemical changes
(c) Frost action
(d) Mechanical forces
4. Which of the following has the smallest soil particles?
5. Rise in temperature of water due to addition of hot water into it is known as
(a) Air pollution
(b) Water pollution
(c) Thermal pollution
(d) Soil pollution
6. If there were no atmosphere surround the earth, then the temperature of the earth will-
(b) Increases during day decreases during night
(c) Remains unaffected
7. The two forms of oxygen found in the atmosphere are-
(a) Water & oxygen
(b) Ozone & oxygen
(c) Water & carbon-dioxide
(d) Water & ozone
8. Which of the following is a non-biodegradable pollutant?
(b) Fruits and vegetables
9. Find the incorrect statement ?
(a) 60% of the global greenhouse effect is due to CO2.
(b) Ozone is highly poisonous to living things.
(c) Bacillus ramous causes ammonification
(d) All biochemical reactions occur in the medium of alcohol
10. Which of the following measures can be taken to reduce the wastage of energy?
(a) Preparation of smokeless stoves
(b) Growing fuel wood trees
(c) Use of biogas
(d) All of these