PSEB Punjab Board Class 7 Social Science Textbook Solution Chapter 3 Atmosphere and Temperature Exercise Questions and Answers
Chapter 3
Atmosphere and Temperature
(I) Answer the following questions in about 1 – 15 words.
(1) What do you understand by the Atmosphere?
Ans: Our earth is surrounded by a cover of air which is called atmosphere that extends upto 1600km in height.
(2) Why we study atmosphere in geography?
Ans: We study about the atmosphere in geography because the various elements of atmosphere – i.e. air, temperature, winds etc affect the physical environment of earth.
(3) Which is called Tropopause limit.
Ans: The upper layer of stratosphere is called tropopause limit which is ideal for flying of airplanes.
(4) What do you understand by exosphere?
Ans: The upper limit of Ionosphere is called exosphere. It contains electronically charged particles and dense gasses like Hydrogen and Helium.
(5) What are the elements other than the gases present in the atmosphere.
Ans: The elements other than gases that are present in the atmosphere are water vapor, dust particles, temperature, humidity.
(6) What is air pollution?
Ans: The foreign substances in the atmosphere are called air pollutants and causes air pollution. The natural causes of air pollution are volcanoes whereas the human causes of in Pollution are burning of fuel, industrialization, release of carbon particles etc.
(7) What is temperature and what are the unit of measuring the temperature.
Ans: The heat of the air is called temperature.
The unit measuring temperature is degrees in Celsius and Fahrenheit.
(8) Why is the temperature very high on the equator?
Ans: The temperature is very high on the equator as it receives direct sunrays and it becomes very hot.
(II) Give answers to the following question in about 50-60 words.
(1) What are the main factors that cause air pollution?
Ans: The main factors that causes air pollution are as follows:
(i) Solid and gaseous air pollutants like dust particles, smoke etc.
(ii) Burning of fuels that release carbon particles.
(iii) Exhaust materials of automobiles.
(2) Write the ratio of main gases in the air.
Ans: The ratio or contents of gases in the air are as follows:
Nitrogen – 78.03%, Oxygen – 20.9%, Argon – 0.94%, Carbon dioxide – 0.03%, Hydrogen – 0.01%.
(3) In which layer of the atmosphere the ozone gas exist. Why is it so important?
Ans: The ozone gas exist in the stratosphere layers of the atmosphere. It is important because the ozone layer or the ozone gas absorbs the ultra violet rays of the sun which is harmful for human life.
(III) Fill in the blanks.
(1) As we go up to the hills temperature ______.
Ans: Decreases.
(2) The main sources of the temperature are ______ and ______.
Ans: Sun, internal part of earth.
(3) The ozone gas absorbs ______ rays.
Ans: Ultra violet.
(4) The electrically charged particles are found in ______ layer.
Ans: Thermosphere (ionosphere).
(5) The wireless communication system works under _____ waves.
Ans: Radio.
(6) _____ gas is found in maximum quantity in atmosphere.
Ans: Nitrogen.
Also See – PSEB Class 7 Social Science Chapter 2 The Internal and External face of the Earth Question Answer