Subject :NSO Class : Class 8
There are two bottles of glass, one bottle is two third filled with water and another bottle is filled one third with water. When we blow across the mouth of each bottle, then
(i) The bottle with the less air in it gives the note of higher pitch
(ii) The shorter the air column, the higher the pitch of the note produced.
A Both (i) and (ii) are correct and (ii) is the correct explanation of (i).
B Both (i) and (ii) are correct but (ii) is not the correct explanation of (i).
C Only (i) is correct.
D Only (ii) is correct.
Ans 1:
Class : Class 8
Pollution---------------
The term pollution belongs to the Latin words pollution, which is the process of making the invironmant, pollution is the contamination of natural resource like air, water and land with harmful(toxing and poisonous) substance.
Pollution is the biggest problem in our country. Pollution is very harmful for our health. It can causeany deasese, smoke of vehicles, factories and burning of trees release harmful gases such as sulfore dioxide and carbon monoxide, when we breath poisonous gas we might cause cancer, asthma and lung deaseses, polluted air causes acid rain. Acid rain make the water and lakes poisonous also destroy the aquatic animals.
We can control pollution in the following base:- growing more trees and plants to reduce in creasing green house effect. Use recycle paper to save trees. In courage use of public transport. Washing clothes, cleaning utensils or taking a bath near water bodies such as lakes, rives and ponds should be restricted. Use less fertilizers and pesticides. Death bodies should be cremated or buried and not desposed of in a river or lakes. Use of less polluting anergy resource like hidroelectric energy, solar energy and wind energy. Replace would, col kerosine with clean fuel, LPG for domestic use through the garbage at proper place. Compost pit should be made for biodegradable waste. Plastic bags should be reduced. Pollution control rules inforced by the government should be followed sticktly. Use morder automobile engines in vehicles which bring about complete combustion of fuel. This reduce the release of carbon monoxide and smoke. Domestic sea ways should be treated at the sea ways treatment plants to remove toxic substance before being released into water bodies.
Due to human greediness and misuse of freeness of doing anything lead them to words serious degradation and mismanagement of resource. So, the invironmantal issue needs to be solved on urgent basis by the effort of all offers. It requires a joined effort from everyone to get control over the pollution. So, it needs leamitation over all the causes of the invironmantal pollution.