Temperature | Class 6 | Geography | Chapter 5 | Maharashtra State Board
In this educational video, we will explore the various aspects of temperature and its distribution on the earth's surface. Through engaging activities and experiments, we will demonstrate the factors that affect the distribution of sunrays on the earth, as well as the heating and cooling of water and land. We will also delve into the effects of greenhouse gases on the earth, and use experiments to illustrate the movement of warm and cold currents in the ocean. To help you better understand temperature distribution, we will introduce a new concept called isolines, and explain it using a map. Finally, we will take a detailed look at thermometers and how they measure temperature. By the end of this video, you will have gained a comprehensive understanding of temperature, its distribution on earth, and the various factors that affect it. So, join us in this informative and exciting journey to explore the world of temperature!
Questions & Answers
A. Where am I?
1. The isotherm 0°C runs in my surroundings.
Ans. Northern Asia, Northern Canada.
2. The mean annual temperature is 25°C around me.
Ans. Central Africa.
3. The mean annual temperature around me is 10°C.
Ans. Northern Europe, Central Asia, USA.
B. Who am I?
1. I connect places of equal temperature.
Ans. Isotherm.
2. I am useful for measuring the correct temperature.
Ans. Simple Thermometer.
3. I get heated due to the land or water near me.
Ans. Air.
4. Land and water get heated due to me.
Ans. Sunrays.
C. Answer the following.
1. Explain with a diagram, the effect of the spherical shape of the earth on the temperature at different latitudes.
Ans.
Due to the spherical shape of the earth and the resultant curvature of the surface, sunrays occupy a larger or a lesser area.
Equatorial regions which receive straight rays of the sun occupy less space and heat received is more.
Polar regions receive slant rays of the sun occupy larger space but the heat received is less.
2. What is the relation between the latitudinal extent and temperature of region?
Ans.
0° and 23° 30′ North and South perpendicular rays. Temperatures are higher throughout the year.
23° 30′ and 66° 30′ North and South receive extreme slant rays. Temperatures are moderate.
66° 30′ and 90° North and South receive extreme slant rays. Temperatures are very low.
3. What makes the isotherms run zigzag over continental areas?
Ans.
Temperatures of continental areas vary as per their height from the sea level. As one moves higher up from the surface of continental areas, the temperature of the air decreases.
Due to difference in the height of the continental areas, the distance between the isotherms varies.
Vegetation cover, urbanization, industrialization also leads to diversity in the distribution of temperature. Thus, these factors also make the isotherms run zigzag over continental areas.
E X T R A
A. Fill in the blanks with right alternative.
The main factor which influences the distribution of temperature is latitude. (ocean current, longitude, latitude)
Carbon dioxide gas can hold heat within itself in the atmosphere. (Carbon-dioxide, Oxygen, Hydrogen)
Isotherms are fairly parallel to the latitudinal line in the Southern hemisphere. (Northern, Western, Southern)
Nagpur receives extreme climate. (extreme, equable, moderate)
When an ocean current flows from the frigid to the torrid zone, it reduces the temperature of the coast in the torrid zone. (increase, reduces, equal)
Isotherms are lines that connect places with the same temperature after avoiding the effect of the height. (different, same, moderate)
Substance used in a thermometer tube is mercury. (water, mercury, oil)
The freezing point of mercury is -39°C. (-39, -49, -59)
The freezing point of alcohol is -130°C. (-110, -120, -130)
Air temperature is measured in Celsius. (Celsius, Fahrenheit, Grams)
B. Give one word for the following.
1. The sunrays which occupy less area.
Ans. Perpendicular.
2. The sunrays which occupy larger area.
Ans. Slant.
3. The climate in coastal areas.
Ans. Equable.
4. The climate in continental areas.
Ans. Extreme.
5. Food for fishes.
Ans. Plankton.
6. Main factor responsible for influencing the distribution of temperature.
Ans. Latitude.
7. Measuring daily temperature.
Ans. Thermometer.
C. Name the following.
1. Temperature zones on the earth.
Ans. Torrid zone, temperature zone and frigid zone.
2. Lines drawn on a map by joining all the points having the same value.
Ans. Isolines.
3. Two cold currents.
Ans. Canaries and Peruvian current.
4. Two warm currents.
Ans. Equatorial and Brazil current.
D. Answer the following questions in one sentence.
1. What is diurnal range of temperature?
Ans. The difference in maximum and minimum temperature of a day is called diurnal range of temperature.
2. What factors leads to horizontal currents in the ocean?
Ans. Horizontal currents develop in the ocean due difference in temperature density of water and winds.
3. What is the advantage of the convergence of warm and cold current?
Ans. The convergence of warm and cold current favours the growth of plankton.
4. What are isolines?
Ans. Lines drawn on a map by joining all the points having the same value are called isolines.
5. Where is the distance between the isotherms parallel?
Ans. The distance between the isotherms is parallel from South Pole to the Tropic of Capricorn.
6. Which factors lead to diversity in the climate of different regions?
Ans. The factors which lead to diversity in the climate of different regions are nearness to the sea, continentality, height above the mean sea level and physical level.
7. What is an annual range of temperature?
Ans. The difference in the mean temperatures of summer and winter is called an annual range of temperature.
E. Give geographical reasons.
1. There is unequal distribution of heat received from the Sun.
Ans. The unequal distribution of heat received from the Sun is because:
The earth is spherical in shape.
The rays which fall on the equator are straight, occupy less area and give more heat.
The rays which fall on the curvature i.e., on the polar regions are slant rays which occupy large area and give less heat.
2. The temperature near the sea level is higher and it decreases in the mountainous region.
Ans.
Firstly, the sea water gets heated by the rays of the sun.
The absorbed heat is later radiated into the atmosphere.
So, the layer of air close to the surface gets heated.
This heat gets transferred vertically to the adjacent upper layers of air.
Therefore, the temperature near the sea level is higher and it decreases at the mountainous region.
3. In the coastal areas, as compared to continental areas, the temperature of air is lower during the day but warmer at night.
Ans.
There is difference in the heating and cooling of land and water.
The air over the land gets heated faster and also cools rapidly.
The air over the water gets heated slowly and also loses the heat in a slower manner.
The temperature of air is lower during the day but warmer at night, in the coastal areas when compared to continental areas.
4. Greenhouse gases lead to increasing temperature of the earth.
Ans.
Some gases in the atmosphere like carbon dioxide and water vapour can hold the heat within themselves for a long period of time.
Due to the gases, the temperature of air in the atmosphere increases.
Thus, greenhouse gases lead to increasing temperature of the earth.
5. Regions, where warm and cold currents converge, are favourable for the growth of fisheries.
Ans.
Regions, where warm and cold currents converge, are favourable for the growth of planktons.
Planktons are the food for fishes.
Fishes travel here in large numbers.
They breed in warm waters and increase the number of fishes.
Therefore, regions where warm and cold currents converge favour the growth of fisheries.
F. Answer the following.
1. Explain the movement of ocean currents from equator to the polar region.
Ans. Due to temperature differences, both upward and horizontal currents develop in the ocean. Besides temperature differences, factors like winds and differences in the density of water also give rise to horizontal currents. These ocean currents flow from the equator to the polar region and from the polar region to the equator.
2. Explain the effect of the ocean current flows from the frigid to the torrid zone.
Ans. When an ocean current flows from the frigid to the torrid zone, it reduces the temperature of the coasts in the torrid zone. When a current flows from the torrid to the frigid zone, it increases the temperature of the coasts in the frigid zone.
3. Identify the temperature zones.
Ans. There are three temperature zones namely torrid, temperature and frigid zones.
4. Tell the factors influencing temperature.
Ans. Factors influencing temperature are latitude, winds, nearness to the sea, continentality, vegetation cover, cloud cover, physical set up, height above sea level and industrialisation.
5. Describe the structure of a thermometer.
Ans. A vacuum glass tube is filled with mercury or alcohol is mounted on a wooden board. There are two temperature scales showing Celsius and Fahrenheit.
6. Describe the global distribution of temperature with its characteristics.
Ans. The isotherms in the southern hemisphere are fairly parallel to the latitudinal lines. From South Pole to the Tropic of Capricorn the distance between these lines is almost equal. As the proportion of land in the southern hemisphere is limited, temperatures in these parts are largely influenced by latitude.
In the northern hemisphere, the distance between these lines varies. In this hemisphere, the proportion of land is comparatively greater. This affects the distribution of temperature. These effects are seen in the form of variations in the distance between the isotherms and curved nature of these lines.
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