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Class 10 Geography Chapter 1 Important Questions and Answers Weather and Climate
Kerala Syllabus Class 10 Social Science Geography Chapter 1 Weather and Climate Important Questions
Weather and Climate Class 10 Important Questions
Question 1.
What is the name given to the atmospheric conditions such as temperature, pressure, wind, humidity and precipitation for a shorter period of time?
a) Climate
b) Weather
c) Temperature
d) Humidity
Answer:
b) Weather
Question 2.
Which is the earth’s main source of energy?
a) Wind
b) Rain
c) Sun
d) Cloud
Answer:
c) Sun
Question 3.
What is the name of the process of producing energy in the sun?
Answer:
Nuclear fusion
Question 4.
Define Insolation.
Answer:
The amount of sun’s rays reaching the earth’s surface is called Insolation.
Question 5.
What do you mean by Terrestrial Radiation?
Answer:
The re-radiation of energy in the form of long waves from the earth’s surface is called Terrestrial radiation.
Question 6.
In which thermal region does the sun’s ray fall vertically?
Answer:
Torrid Zone
Question 7.
Which instrument is used to measure atmospheric pressure?
Answer:
Barometer
Question 8.
What is the low pressure zone formed due to high temperatures in the equatorial region?
Answer:
Equatorial low pressure belt
Question 9.
What is the name given to winds that blow constantly in a certain direction throughout the year?
Answer:
Permanent winds
Question 10.
Define Humidity.
Answer:
The invisible water content in the atmosphere is called Humidity.
Question 11.
What is the local wind that blows through the Sahara desert?
Answer:
Harmattan
Question 12.
Name the planetary winds. (MARCH 2021)
Answer:
Trade winds , Westerlies and Polar winds.
Question 13.
Friction is one of the factors that influences the speed and direction of wind. Mention the other factors.
(FIRST TERM 2019)
Answer:
Pressure gradient and Coriolis force
Question 14.
What are the difference between the Weather and Climate?
Answer:
| Weather | Climate |
| It is the study of atmospheric conditions for a short period of time. | It is the study of the average weather condition observed over a long period of time. |
| It is short term phenomenon | It is a long term phenomenon |
| Weather changes frequently | It does not change frequently |
| It depends on a smaller areas like district or state | It depends on a larger area like state or country |
Question 15.
What are the main differences between short waves and long waves?
Answer:
Energy is radiated in the form of short waves from hotter objects. Due to high frequency, the short waves traverse through the atmosphere without obstruction. Objects with relatively less heat radiate energy in the form of long waves. Due to low frequency, long waves will be absorbed or reflected by the atmospheric particles.
Question 16.
What is Terrestrial Radiation? How does this affect atmospheric temperature?
Answer:
The re-radiation of energy in the form of long waves from the earth’s surface is called Terrestrial radiation. The absorption of terrestrial radiation by the atmospheric gases such as carbon dioxide heats up the atmosphere. This phenomenon is tenned as Green House Effect.
Question 17.
Explain Conduction, Convection, Advection.
Answer:
Conduction: Heat is transferred to the lower part of the atmosphere which is directly in contact with the
surface of the earth.
Convection: As the heated air expands and rises up, heat is transferred to higher reaches of the atmosphere. Advection: Heat is transferred horizontally through wind.
Question 18.
When is the maximum and minimum temperature recorded in a day? Why?
Answer:
The temperature recorded at 2pm is considered as the maximum temperature of the day by the meteorologists. The surface temperature of the earth gradually decreases in the afternoon due to the decrease in intensity of insolation as well as the simultaneous terrestrial radiation. The earth’s surface as well as the atmosphere get cooled by more energy loss through terrestrial radiation during night. Thus the temperature recorded just before the sun rise is considered as the minimum temperature of the day.
Question 19.
What are the Isotherms? What is the significance of these in the study of climate?
Answer:
Data regarding the temperature are being utilized for climatic studies and further analysis. Plotting the temperature recorded at specific places, smooth curved lines are drawn connecting the places having equal temperature. These imaginary lines are called Isotherms. Isotherm maps are very useful for analysing temperature distribution.
Question 20.
How is the Equatorial Low Pressure Belt formed? What is the specialty of this belt?
Answer:
The expansion and rising up of air due to high temperature prevailing in the equatorial region is the cause for the formation of Equatorial Low Pressure Belt. This zone of vertical air currents is devoid of winds. Being the windless zone, this pressure belt is called Doldrum.
Question 21.
How are the south-west monsoon winds formed? W hat is the significance of these in India?
Answer:
During summer the South Asian land masses, especially the Indian Sub Continent, gets heated up intensely and severe low pressure develops. Wind blows towards the land mass from the Indian Ocean where comparatively high pressure prevails. These winds blowing as South West winds due to Coriolis effect causes widespread rainfall on entering the land. This is South west monsoon. This south west monsoon is the main reason for the rainy season in India.
Question 22.
What is relative humidity? How is this calculated?
Answer:
The ratio between the actual amount of water present in the atmosphere and the total waterholding capacity of atmosphere at that particular temperature and time is referred to as Relative Humidity. It is expressed in percentage.
Relative Humidity = \(\)\frac{\text { Absolute Humidity }}{\text { Total water holding capacity of the atmosphere }}\(\) × 100
Question 23.
Explain how the Coriolis force affects the direction of winds. (FIRST TERM 2023)
Answer:
One of the major factors influencing the direction of winds is the Coriolis Force. Owing to the Coriolis effect, the winds will deflect towards the right of its direction in the Northern Hemisphere and towards the left of its direction in the Southern Hemisphere.
Question 24.
What is atmospheric pressure? What are the main factors influencing the atmospheric Pressure?
Answer:
The weight exerted by the atmospheric air over the earth’s surface is termed as Atmospheric Pressure. Barometer is the instrument used to measure atmospheric pressure.
Factors affecting atmospheric pressure are:
- Temperature: Atmospheric air expands on getting heated, and rises up. Thus low pressure regions are formed. This rising air gradually cools, contracts and subsides to form high pressure regions.
- Altitude: As the density of atmospheric gases decreases with increase in altitude, atmospheric pressure gradually decreases. The vertical variation of atmospheric pressure is at the rate of about lmb per 10 metres.
- Humidity: As the humidity increases, the water molecules displace the heavier gases in the atmosphere like nitrogen and oxygen. The atmospheric pressure becomes low, as humid air is lighter than dry air.
Question 25.
How is energy produced in the sun? What is the amount of solar energy reaching the Earth?
Answer:
Sun is the sole source of energy for the earth. Energy is produced in the sun by nuclear fusion. Massive amount of energy continuously produced in the sun through nuclear fusion is emitted in the form of short waves. Only a small amount of energy radiated from the sun reaches the earth’s surface (approximately one part of 200 million). The amount of sun’s rays reaching the earth’s surface is called Insolation.
Question 26.
What is earth’s heat budget? How does this help in maintaining earth as a living planet?
Answer:
Almost entire energy reaching the earth as insolation is radiated back every day Thus the surface temperature of the earth remains balanced without becoming extremely hot or cold. This process of heat balancing is called the Heat Budget of the Earth. Consider the total amount of solar energy reaching the top of the atmosphere of the earth as 100 units. Out of this, 35 units will be reflected back and 14 units will be absorbed by the atmospheric particles. The total amount of energy reaching the surface of the earth is estimated as 51 units. Out of this, 34 units will be transferred to the atmosphere through the processes of heat transfer such as conduction and convection. By re-radiating 17 units of energy directly from the earth’s surface and 48 units from the atmosphere, the entire energy received by the earth and its atmosphere gets sent back.
Question 27.
How winds are formed? What are the factors that influence wind direction and speed?
Answer:
Winds are the horizontal movements of air from high pressure areas to low pressure areas.
- One of the major factors influencing the direction of winds is the Coriolis Force. Owing to the Coriolis effect, the winds will deflect towards the right of its direction in the Northern Hemisphere and towards the left of its direction in the Southern Hemisphere.
- The speed and intensity of winds are influenced mainly by two factors.
- Pressure gradient is the change in pressure over a horizontal distance. If there is considerable change in pressure between nearby places, it indicates high pressure gradient. If there is no considerable difference of pressure over horizontal distance, pressure gradient is said to be low. At places where there is high pressure gradient, winds will be strong.
- The friction caused by hills, mountains, forests and man-made structures will obstruct the free flow of winds.
Question 28.
What are Periodic winds? Explain with examples.
Answer:
Winds subjected to the periodic reversal of their direction are termed as Periodic winds. Diurnal winds such as the land breezes, sea breezes, mountain breezes and valley breezes, as well as the monsoon winds which repeat in summer and winter, are periodic winds.
a) Permanent Winds
The winds blowing constantly over a particular direction throughout the year are called Permanent winds. These winds are also known as prevailing winds and planetary winds. These winds blow between global pressure belts. Trade winds, Westerlies and Polar winds are the major permanent winds.
ITCZ
The equatorial low pressure region where the trade winds from the Northern Hemisphere and the Southern Hemisphere converge is known as Inter Tropical Convergence Zone (ITCZ). ITCZ shifts with the apparent movement of the sun.
b) Periodic Winds: Winds subjected to the periodic reversal of their direction are termed as Periodic winds. Diurnal winds such as the land breezes, sea breezes, mountain breezes and valley breezes as well as the monsoon winds which repeat on summer and winter are periodic winds.
Land Breezes and Sea Breezes
The air in contact with the land also gets heated up and ascends as the land heats up quickly during the daytime. This leads to the formation of low pressure over the land which causes the comparatively cooler air to blow from the sea. This is known as sea breeze.
As the land cools faster than the sea during the night it would be high pressure over the land and low pressure over the sea. This results in the movement of air from the land to sea. This is the land breeze.
Mountain Breezes and Valley Breezes
During night, air along the mountain slopes cools, contracts and moves down slope. These winds are called mountain breezes. During day time, the heating by sunlight and rising up of air along the mountain slopes make the wind to blow up slope from the valley. These winds are called valley breezes.
Monsoon Winds
• The term ‘monsoon’ implies the seasonal reversal in the wind pattern.
During summer the South Asian land masses, especially the Indian Sub Continent, gets heated up intensely and severe low pressure develops. Wind blows towards the land mass from the Indian Ocean where comparatively high pressure prevails. These winds blowing as South West winds due to Coriolis effect causes widespread rainfall on entering the land. This is Southwest monsoon.
During winter, as the northern land masses get severely cooled, high pressure develops over North India. This causes the winds to blow continuously from the land towards the Indian Ocean as north east winds.
c) Local Winds: Local winds are winds formed as a result of local differences in temperature and pressure in different parts of the world. Most of the local winds are periodic in nature. These winds are known by local regional names. Details regarding a few such local winds:
| Local Winds | Region | Characteristics |
| Loo | North Indian Plains | Hot wind |
| Chinook | Slopes of Rocky Mountains in North America | Dry hot wind |
| Foehn | Slopes of Alps Mountain in Europe | Dry hot wind |
| Harmattan | Sahara Desert in Africa | Relief to intense heat |
d)Variable Winds: Winds of short duration, of which the intensity or direction cannot be predicted are called variable winds. Cyclones and Anticyclones belong to this category.
Cyclones
• Cyclones are low pressure systems towards which winds whirl from the surroundings.
Even if the cyclones developed over the tropical region are comparatively lesser in diameter, they are devastative than temperate cyclones. Tropical cyclones originate over tropical oceans. The tropical cyclones moving in northwest direction over the oceans, get dissipated on hitting the lands. Different temperature conditions prevailing on land and also the friction causes the dissipation of cyclones on entering land.
The tropical cyclones cause intense rainfall and strong whirlwinds along the coasts. They are known by different names in different parts of the world such as Hurricanes, Typhoons, Willy Willies, Tornadoes etc. Temperate cyclones are formed in temperate regions where warm and cold air masses meet. Even if the temperate cyclones are larger in diameter, they are less devastative. Unlike the tropical cyclones, these low-pressure systems can move over land also. The direction of flow of air into the cyclones are anticlockwise in the Northern Hemisphere and southern Hemisphere clockwise in the Southern Hemisphere.
Anticyclones
- Anticyclones are high pressure system from which winds whirl outwards. Generally anticyclones do not cause atmospheric disturbances.
- The direction of flow of winds from anticyclones is clockwise in the Northern Hemisphere and anticlockwise in the Southern Hemisphere.
Question 29.
What is Humidity? What is the difference between Absolute Humidity and Relative Humidity?
Answer:
The invisible water content in the atmosphere is called Humidity.
- Actual amount of water vapour present per unit volume of atmosphere is called Absolute humidity. Hygrometer is the instrument used to measure atmospheric humidity.
- The ratio between the actual amount of water present in the atmosphere and the total waterholding capacity of atmosphere at that particular temperature and time is referred to as Relative Humidity. It is expressed in percentage.
- Relative humidity can be estimated based on the difference in temperature recorded in wet and dry bulb thermometers.
- Relative Humidity = \(\)\frac{\text { Absolute Humidity }}{\text { Total water holding capacity of the atmosphere }}\(\) × 100
Total water holding capacity of the atmosphere
Question 30.
Match Column A with Column B.
| Cirrus Cloud | Cotton wool-like clouds |
| Cumulus Cloud | Thin, delicate, feather-like clouds |
| Nimbus Cloud | Thick-layered clouds |
| Stratus Cloud | Dark,rain-bearing clouds |
Answer:
| Cirrus Cloud | Thin, delicate, feather-like clouds |
| Cumulus Cloud | Cotton wool-like clouds |
| Nimbus Cloud | Dark, rain-bearing clouds |
| Stratus Cloud | Thick-layered clouds |
Question 31.
Complete the missing columns in the given table.
| Mountain Breeze | a) |
| b) | During day time,the heating by sunlight and rising up of air along the mountain slope. |
| Land Breeze | c) |
| d) | d) During the day, it blows from the high-pressured sea |
Answer:
| Mountain Breeze | During night, air along the mountain slopes cools, contracts and moves down slope. |
| Valley Breeze | During day time, the heating by sunlight and rising up of air along the mountain slope. |
| Land Breeze | At night the pressure blows from high land to sea. |
| Sea Breeze | During the day, it blows from the high-pressured sea |
Question 32.
What is condensation? What are the different forms of condensation? Explain.
Answer:
Condensation
The atmospheric moisture is visible only when the water vapour condenses to form tiny droplets of water.
Different forms of Condensation:
a) Dew: During the night, as the earth’s surface cools down, the atmosphere close to the earth’s surface also cools. The water vapour condenses to form tiny droplets of water which may cling on to the grass tips, leaf blades as well as other cold surfaces.
b) Frost: Whenever the atmospheric temperature falls below 0° Celsius, especially during nights, tiny crystals of ice are formed instead of dew.
c) Mist and Fog: When the atmosphere gets cooled, the water vapour condenses to form tiny droplets of water and remains suspended in the lower atmosphere. Fog or mist is formed as a result of condensation of water vapour around tiny dust particles in the lower atmosphere. Fog and mist can be distinguished based on the range of visibility through them.
d) Clouds: Clouds are formed as a result of condensation around the tiny dust particles in the atmosphere. The water droplets thus formed are less than 0.001 cm in diameter. This is why, they remain suspended in the atmosphere.
Clouds can be classified based on their form as well as the height at which they are formed.
- Thin, delicate, feather-like clouds formed at very high altitudes are called Cirrus clouds.
- Thick-layered clouds, usually formed in the lower atmosphere, are called Stratus clouds.
- Cotton wool-like clouds formed as a result of intense convection currents, are called Cumulus clouds. These clouds have great vertical development.
- Dark, rain-bearing clouds, formed in the lower part of the atmosphere, are called Nimbus clouds. The dark colour is due to the thick concentration of water droplets which does not allow light to penetrate through them.
- These clouds are not usually seen independently. Mostly we see the combinations of different types of clouds. Such clouds are called as cirro stratus, strato cumulus, cumulo nimbus, nimbo stratus etc.
Question 33.
Monsoon winds are classified as southwest and northeast. Validate the statement.
Answer:
The term ‘monsoon’ implies the seasonal reversal in the wind pattern.
- During summer the South Asian land masses, especially the Indian Sub Continent, gets heated up intensely and severe low pressure develops. Wind blows towards the land mass from the Indian Ocean where comparatively high pressure prevails. These winds blowing as South West winds due to Coriolis effect causes widespread rainfall on entering the land. This is Southwest monsoon.
- During winter, as the northern land masses get severely cooled, high pressure develops over North India. This causes the winds to blow continuously from the land towards the Indian Ocean as north east winds. These winds which are generally dry in nature are called Northeast monsoon winds.
Question 34.
Explain how equatorial low pressure belt and subtropical high pressure belts are formed. Identify the planetary wind that blows between these pressure belts.
Answer:
- The expansion and rising up of air due to high temperature prevailing in the equatorial region is the cause for the formation of Equatorial Low Pressure Belt.
- The rising warm air along the equatorial region moves polewards as upper air winds which gradually cool and subside at about 30° North and 30° South latitudes. This results in the formation of Sub Tropical High Pressure Belts.
- The planetary wind that blows between these pressure belts are trade winds and westerlies.
Question 35.
What are variable winds? Distinguish between cyclones and anticyclones. (MODEL 2020)
Answer:
Winds of short duration, of which the intensity or direction cannot be predicted are called variable winds. Cyclones and Anticyclones belong to this category.
Cyclones: Cyclones are low pressure systems towards which winds whirl from the surroundings. Even if the cyclones developed over the tropical region are comparatively lesser in diameter, they are devastative than temperate cyclones. Tropical cyclones originate over tropical oceans. The tropical cyclones moving in northwest direction over the oceans, get dissipated on hitting the lands. Different temperature conditions prevailing on land and also the friction causes the dissipation of cyclones on entering land. The tropical cyclones cause intense rainfall and strong whirlwinds along the coasts. They are known by different names in different parts of the world such as Hurricanes, Typhoons, Willy Willies, Tornadoes etc. Temperate cyclones are formed in temperate regions where warm and cold air masses meet. Even if the temperate cyclones are larger in diameter, they are less devastative. Unlike the tropical cyclones, these low-pressure systems can move over land also. The direction of flow of air into the cyclones are anticlockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.
Anticyclones: Anticyclones are high pressure system from which winds whirl outwards. Generally anticyclones do not cause atmospheric disturbances. The direction of flow of winds from anticyclones is clockwise in the Northern Hemisphere and anticlockwise in the Southern Hemisphere.
Question 36.
What is Precipitation? What are the different forms of Precipitation? Explain their characteristics.
Answer:
As a result of continuous condensation, the size of water droplets within the clouds gradually increases. As the size of water droplets grows beyond the limit of resistance against gravity, water droplets will be released from the clouds and may fall on earth in various forms. This is termed as precipitation. Rainfall, snow fall and hailstones are the different forms of precipitation.
- Rainfall is the common and familiar manifestation of precipitation which is in the form of water droplets.
- Temperature falls below 0° Celsius in cold climatic regions as well as in temperate regions during winter. In such places, precipitation occurs in the form of tiny crystals of ice. This form of precipitation is called snowfall.
- The water droplets released from the clouds are subjected to repeated condensation at different levels of atmosphere. It reaches the earth in the form layered ice pellets. These are termed as hailstones.
Question 37.
List out the global pressure belts. Explain any two global pressure belts. (FIRST TERM 2022,2023)
Answer:
(Refer: Topic 4)
Global Pressure Belts: Temperature is inversely proportional to pressure. Thus the lowest atmospheric pressure might be experienced in the equatorial region and the highest might be in the polar regions. The pressure should therefore increase from the equator towards the poles. But actually this is not the case. Distinct pressure conditions prevail at certain specific zones due to the influence of the rotation of the earth.
- Different pressure belts are formed along certain specific latitudinal zones. These are called Global Pressure Belts.
- The expansion and rising up of air due to high temperature prevailing in the equatorial region is the cause for the formation of Equatorial Low Pressure Belt.
- This zone of vertical air currents is devoid of winds. Being the windless zone, this pressure belt is called Doldrum.
- Atmospheric conditions along the poles are just opposite to that in equatorial region. Polar High Pressure Belts are formed as a result of the contraction and subsidence of cold air.
- The rising warm air along the equatorial region moves polewards as upper air winds which gradually cool and subside at about 30° North and 30° South latitudes. This results in the formation of Sub Tropical High Pressure Belts.
- At about 60° North and 60° South latitudes, normally high pressure zones should be formed due to lower temperature conditions. But owing to the continuous throwing up of air along these regions caused by the influence of the rotation of the earth Sub Polar Low Pressure Belts are formed.
- As the temperature conditions vary with the apparent movement of the sun, the global pressure belts are subjected to relative shifts.
- Global pressure belts may shift to about 5° to 10° northwards during summer season and shift southward during winter season. This shifting of global pressure belts has decisive influence on global climate.
The pressure differences in the atmosphere are largely noticeable through air movements. There are two types of air movements in the atmosphere.
- Air Currents: Air Currents are the vertical movements of air.
- Winds: Winds are the horizontal movements of air from high pressure areas to low pressure areas.
Temperature is inversely proportional to pressure. Thus the lowest atmospheric pressure might be experienced in the equatorial region and the highest might be in the polar regions. The pressure should therefore increase from the equator towards the poles. But actually this is not the case. Distinct pressure conditions prevail at certain specific zones due to the influence of the rotation of the earth. Different pressure belts are formed along certain specific latitudinal zones. These are called Global Pressure Belts.
The zone of vertical air currents is devoid of winds. Being the windless zone, this pressure belt is called Doldrum. Atmospheric conditions along the poles are just opposite to that in equatorial region. Polar High Pressure Belts are formed as a result of the contraction and subsidence of cold air. The rising warm air along the equatorial region moves polewards as upper air winds which gradually cool and subside at about 30° North and 30° South latitudes. This results in the formation of Sub Tropical High Pressure Belts. At about 60° North and 60° South latitudes, normally high pressure zones should be formed due to lower temperature conditions. But owing to the continuous throwing up of air along these regions caused by the influence of the rotation of the earth Sub Polar Low Pressure Belts are formed. As the temperature conditions vary with the apparent movement of the sun, the global pressure belts are subjected to relative shifts. Global pressure belts may shift to about 5° to 10° northwards during summer season and shift southward during winter season. This shifting of global pressure belts has decisive influence on global climate.
Question 38.
How does rain occur? Prepare a note explaining the different types of rain.
Answer:
As a result of continuous condensation, the size of water droplets within the clouds gradually increases. As the size of water droplets grows beyond the limit of resistance against gravity, water droplets will be released from the clouds and may fall on earth in various forms. This is termed as precipitation. Rainfall, snow fall and hailstones are the different forms of precipitation.
- Rainfall is the common and familiar manifestation of precipitation which is in the form of water droplets.
- Temperature falls below 0° Celsius in cold climatic regions as well as in temperate regions during winter. In such places, precipitation occurs in the form of tiny crystals of ice. This form of precipitation is called snowfall.
- The water droplets released from the clouds are subjected to repeated condensation at different levels of atmosphere. It reaches the earth in the form layered ice pellets. These are termed as hailstones.
Rainfall
Rainfall is the most familiar form of precipitation.
Types of Rainfall
a) Orographic rainfall or Relief rainfall.
Moisture-laden winds from the sea enter the land and will be raised along the mountain slopes. This leads to condensation and formation of rain clouds along the windward slopes of mountains. Rainfall occurring in this manner is called Orographic rainfall or Relief rainfall.
While the windward slopes of mountains get plenty of rainfall, the descending dry air makes the leeward side rainless. Such regions are called Rain Shadow Regions.
b) Convectional Rainfall
Rainfall occurs in the afternoon during summer season due to the convection process. Rainfall occuring in this manner are called Convectional Rainfall. As the convectional rainfall commonly occurs during afternoons, it is also called 4 O’Clock rains.
c) Cyclonic Rainfall.
In cyclonic systems where warm and cold air meet, the warm air will be raised up to cause condensation and rainfall. This type of rainfall is called Cyclonic Rainfall.
As the boundary lines between warm and cold air masses are known as fronts, this type of rainfall are also called Frontal Rainfall.
Question 39.
Which are the elements of weather?
Answer:
Temperature, Pressure, Wind and Humidity.
Question 40.
Differentiate climate and weather.
Answer:
Weather refers to atmospheric conditions like temperature, pressure, wind, humidity, and precipitation for a short period of time, while climate is the average weather condition experienced over a longer period (about 35 to 40 years) across a larger area.
Question 41.
How does climate influence human life and activities?
Answer:
Climate affects the flora and fauna, food habits, dressing, settlement, occupation, physical and mental conditions, and even the colour and race of people. It also determines agricultural practices and influences transport and communication systems.
Question 42.
Energy is produced in the sun by …………………………
Answer:
Nuclear fusion
Question 43.
What are the common units for recording temperature?
Answer:
Degree Celsius and Degree Fahrenheit
Question 44.
What is heat and in which unit is it measured?
Answer:
Heat is the total energy of an object due to molecular movement. It is measured in Joules.
Question 45.
What is Thermal Equator?
Answer:
Imaginary line connecting places with highest mean annual temperature along every longitude is termed as Thermal Equator.
Question 46.
How is temperature defined and what are its units of measurement?
Answer:
Temperature is the degree of hotness of an object. It is measured in units such as Degree Celsius, Degree Fahrenheit, and Kelvin.
Question 47.
Write any two factors that influencing the distribution of Temperature.
Answer:
Latitide and Altitude
Question 48.
Define Normal Lapse Rate.
Answer:
The phenomenon of gradual decrease in temperature at the rate of 6.4° Celsius per kilometre of altitude is termed as Normal Lapse Rate.
Question 49.
Why is the temperature higher near the equator and lower towards the poles?
Answer:
Very, high temperature is experienced along the equatorial regions where the incidence of sun’s rays is almost vertical. Owing to the spherical shape of the earth, the incidence of sun’s rays are more inclined away from the equator towards the poles. Thus the temperature gradually decreases towards both the poles.
Question 50.
How does altitude affect atmospheric temperature?
Answer:
Atmospheric temperature gradually decreases with an increase in altitude.
Question 51.
Define Atmospheric Pressure.
Answer:
The weight exerted by the atmospheric air over the earth’s surface is termed as Atmospheric Pressure.
Question 52.
Which instrument is used to measure atmospheric pressure?
Answer:
Barometer
Question 53.
What are the two main types of barometers?
Answer:
Mercury Barometer and the Aneroid Barometer.
Question 54.
What are isobars?
Answer:
Isobars are smooth curved lines drawn on maps to connect places having equal atmospheric pressure.
Question 55.
What are the two types of air movements in the atmosphere?
Answer:
Air Currents and Winds.
Question 56.
What is the Coriolis effect and how does it influence the direction of winds?
Answer:
One of the major factors influencing the direction of winds is the Coriolis Force.Owing to the Coriolis effect, the winds will deflect towards the right of its direction in the Northern Hemisphere and towards the left of its direction in the Southern Hemisphere.
Question 57.
What are the functions of an anemometer and wind vane?
Answer:
Anemometer is the instrument used to measure the speed of wind. The distance travelled by wind per hour can be estimated using this instrument. Wind Vane is the instrument which indicates the direction of wind.
Question 58.
What is the characteristics of the local wind Chinook?
Answer:
Dry hot wind
Question 59.
What is the Inter Tropical Convergence Zone (ITCZ) and how does it shift?
Answer:
The equatorial low pressure region where the trade winds from the Northern Hemisphere and the Southern Hemisphere converge is known as Inter Tropical Convergence Zone (ITCZ) . ITCZ shifts with the apparent movement of the sun.
Question 60.
What are local winds and how are they named?
Answer:
Local winds are winds formed due to local differences in temperature and pressure. They are periodic in nature and are known by local regional names.
Question 61.
……………………… is the instrument used to measure atmospheric humidity.
Answer:
Hygrometer
Question 62.
What are the factors influencing atmospheric humidity?
Answer:
Atmospheric humidity varies from place to place depending on the temperature and availability of water.
Question 63.
How is relative humidity estimated?
Answer:
Relative humidity can be estimated based on the difference in temperature recorded in wet and dry bulb thermometers.
Question 64.
What is saturation level and saturation point in the atmosphere?
Answer:
The state at which the atmosphere is fully saturated with moistur/water vapour is known as Saturation level and the temperature at which this level is attained is termed as Saturation point.
Question 65.
As the convectional rainfall commonly occurs during afternoons, it is also called ………………………
Answer:
4 O’Clock rains