Geography [1 Mark Question Answer]

Stratosphere contains sufficient amount of ozone which absorbs the extremely hot ultra-violet rays of the sun. It is known as ozone layer.

Troposphere is the layer where all weather conditions occur in different forms.

There is total absence of water vapour in this layer. It extends upto a height of 50 km. The temperature remains constant up to – 55°C.

Troposphere is the lowest and densest layer of atmosphere touching the land surface. It extends from 8km to 18 km. in height

The atmosphere consists of 78% Nitrogen 21% oxygen and 1% other gases.

Weather is the physical condition or state of the atmosphere (temperature, pressure, state of the sky, etc.) at a given locality or an area.

Atmosphere protects the earth from harmful ultra-violet and infra-red rays of the sun.
It controls the hydrological cycle and provides life-giving gases.

The main Greenhouse gases are CFCs (Chlorofluorocarbons) and nitrogen oxides which are emitted by fertilizers industries and transport engines along with carbon dioxide and methane.

Global Warming is the increase in temperature of earth due to enhanced concentration of Greenhouse gases (CFCs) in the atmosphere.

The blanket of air upto 1500 km surrounding the earth is known as atmosphere.

Atmosphere keeps on changing day and night. So the weather changes day-to-day. Great contrasts are found in day and night temperatures. Clouds change wind velocity.

The exosphere allows the gas molecules to easily escape into space due to lack of gravity.

The ionosphere is suited to long-distance communication because radio waves used for this purpose are reflected back to the earth by the electrically charged gas molecules in it.

The stratosphere is crucial to life on the earth because the ozone layer present in it absorbs the harmful ultraviolet radiation of the sun.

The solid particles play an important role in the atmosphere because they act as nuclei for the condensation of water vapour around them.

The amount of water vapour in the atmosphere varies from place to place due to difference in temperature

The earth does not experience extremes of temperature as on other planets due to the presence of the atmosphere.

The ionosphere, which extends from 80 km to 480 km is known as the Thermosphere.

The topmost layer of the atmosphere is called the Exosphere.

The layer of the atmosphere which extends to a height of 80 km above the stratosphere is called Mesosphere.

These are chloro-fluoro carbons and are used as propellants in aerosol cans, refrigerants in refrigerators, air conditioning and as solvent cleaners in the microelectronic industry.

The atmospheric layer closest to the earth is called Troposphere.

The layer of the atmosphere above the troposphere is called Stratosphere.

The warming up of the atmosphere due to trapping of the solar radiation reflected by the earth by gases like carbon dioxide is called Greenhouse effect.

Gradual rise in Earth’s average temperature is called Global Warming.

The upper limit of the troposphere is called Tropopause.

The large depletion of ozone layer in certain parts of the atmosphere is called Ozone hole.

Atmosphere acts like a blanket keeping the earth warm. It absorbs incoming solar radiation and does not allow radiation to escape. So equable temperatures are found.

Stratosphere absorbs the harmful ultra-violet rays of the sun and the troposphere regulates all weather conditions e.g. ideal temperature, rainfall and their impact on human life.