Insolation: ICSE Class 9 Geography solution

Summary

The sun sends out heat and light energy in all directions. This is called solar radiation. Solar radiation includes white light, infrared radiation, and ultraviolet radiation. The sun also gives off tiny particles called ‘Solar Wind’. This energy from the sun is the main source of heat and light for our Earth. The amount of solar energy that Earth receives is called insolation. Only a very small part of the sun’s total energy reaches our planet.

When the sun’s energy reaches Earth, some of it is scattered or absorbed. Out of all the solar energy that comes towards Earth, about 51% reaches the Earth’s surface. Around 35% is reflected back into space. The remaining 14% is absorbed by the atmosphere, including the ozone layer. The Earth’s surface, after getting heated by insolation, sends this heat back into the atmosphere. This heat sent back by the Earth is called terrestrial radiation, and it travels in long waves.

Earth maintains a balance between the incoming heat from the sun and the outgoing heat from its surface. This balance is known as the Heat Balance or heat budget. It’s like a budget for heat, where what comes in should equal what goes out. This balance is important for life. Heat is spread across the Earth through processes like conduction, where air touching the warm ground gets heated. Another way is convection, where warm air or water rises and cooler air or water moves in to take its place, like in sea breezes.

The atmosphere plays a big role in keeping Earth’s temperatures steady. It acts like a blanket. During the day, it absorbs some of the sun’s heat, preventing Earth from becoming too hot. At night, it traps some of the Earth’s heat, preventing it from getting too cold. The atmosphere is heated more by the terrestrial radiation from Earth than by the direct insolation from the sun.

Several factors affect the temperature of a place. Latitude, or how far a place is from the Equator, is one factor. Places near the Equator are hotter because the sun’s rays hit them directly. Places further away, towards the Poles, are colder because the sun’s rays hit them at a slant, spreading the heat over a larger area. This divides Earth into heat zones: the hot Torrid Zone, the mild Temperate Zones, and the cold Frigid Zones.

Altitude, or the height of a place above sea level, also affects temperature. Higher places are generally cooler than lower places. This is because the air is thinner at higher altitudes and the atmosphere is mostly heated from below by the Earth’s surface. The temperature usually drops by about 1°C for every 166 meters you go up. This is called the Normal Lapse Rate.

Distance from the sea influences temperature too. Land heats up and cools down faster than water. So, places near the sea have a moderate climate, with cooler summers and milder winters. During the day, cool air blows from the sea to the land (sea breeze). At night, cool air blows from the land to the sea (land breeze).

The slope of the land can also make a difference. Slopes facing the sun receive more direct sunlight and are warmer than sheltered slopes. Sometimes, in valleys on calm, cold nights, the air at the bottom of the valley can become colder than the air on the slopes above. This is called an inversion of temperature. Winds and ocean currents also play a part by moving warm or cold air and water from one place to another, affecting local temperatures. For example, warm ocean currents can make coastal areas warmer than they would normally be.

Textbook solutions (Morning Star/Total)

Multiple-Choice Questions

1. The sun continuously radiates heat and light energy in all the directions known as:

(a) Energy radiation
(b) Solar radiation
(c) Sun radiation
(d) Heat and light radiation

Answer: (b) Solar radiation

2. Besides white light, infrared and ultraviolet radiation, the sun emits.

(a) Solar Energy
(b) Solar Wind
(c) Heat Energy
(d) All of the above.

Answer: (b) Solar Wind

3. The solar energy received by the earth is called:

(a) Radiation
(b) Insolation
(c) Greenhouse radiation
(d) Precipitation radiation

Answer: (b) Insolation

4. The heat radiated by the earth in the form of long waves is called:

(a) Terrestrial radiation
(b) Heat balance
(c) Conduction
(d) Convection

Answer: (a) Terrestrial radiation

5. When both incoming radiation and outgoing radiation are balanced, it is called:

(a) Convection
(b) Terrestrial radiation
(c) Heat balance
(d) Conduction

Answer: (c) Heat balance

6. Of the insolation 35% is reflected by the atmosphere. How much reaches the earth’s surface.

(a) 14%
(b) 51%
(c) 35%
(d) 34%

Answer: (b) 51%

7. Conduction : ____________ :: Convection : ____________

(a) direct contact; circulatory motion
(b) circulatory motion, direct contact
(c) absorption, transference
(d) transference, absorption

Answer: (a) direct contact; circulatory motion

8. The atmosphere is warmed by A% of insolation and B% of terrestrial radiation regulating earth’s temperature preventing extremes of temperature.

(a) A: 14; B: 34
(b) A: 35; B: 35
(c) A: 14; B: 48
(d) A: 51; B : 17

Answer: (a) A: 14; B: 34

9. The height of a place above the mean sea level:

(a) Latitude
(b) Altitude
(c) Height
(d) Sea level height

Answer: (b) Altitude

10. land : ____________ :: water : ____________

(a) circulation, convection
(b) currents, breeze
(c) conduction, convection
(d) circulation, circumvention

Answer: (c) conduction, convection

11. Sea breeze : daytime :: land breeze : ____________

(a) daytime
(b) night time
(c) dawn
(d) dusk

Answer: (b) night time

12. The increase in temperature in valleys:

(a) Mountain breeze
(b) Normal lapse rate
(c) Inversion of temperature
(d) Valley breeze

Answer: (c) Inversion of temperature

Short Answer Questions

1. What is solar radiation? What is its significance for the earth?

Answer: The sun continuously radiates heat and light energy in all the directions; this is known as solar radiation. Solar radiation is the only primary source of light and heat on the earth. The energy needed for all movement and change on the earth is provided by the sun.

2. What is meant by insolation? State two of its main characteristics.

Answer: The amount of solar energy received by the earth is called insolation. Two of its main characteristics are:

(i) The sun’s energy reaches the earth as short wave rays.
(ii) Only one part out of two billion parts of the sun’s energy reaches the earth; out of the total 100% solar energy, only 51% reaches the earth.

3. State two advantages of convectional heating of the atmosphere.

Answer: Two advantages of convectional heating of the atmosphere are:

(i) It causes the transfer of heat from one medium to another or from one level to another through circulatory movement.
(ii) Convection currents in the atmosphere cause breezes, such as sea breeze and land breeze, and the interchange of these breezes maintains the heat balance.

4. Name four factors that affect the temperature of a place.

Answer: Four factors that affect the temperature of a place are:

(i) Latitude
(ii) Altitude
(iii) Distance from the sea
(iv) Slope of land

5. State the pattern of temperature in mid latitudes.

Answer: In mid latitudes, which are beyond the Torrid Zone, the sun’s rays travel a longer distance and fall in a slanting position, heating up a larger area. Consequently, beyond the Torrid Zone, the temperature goes on falling. Temperature decreases with an increase in latitude on either side of the Equator.

6. What difference is there in the temperatures on a mountain and on a sea shore?

Answer: On a mountain, the temperature is lower at higher altitudes; it is cooler at the top of a mountain than at the bottom.

At a sea shore, areas close to the sea have lower daily and annual ranges of temperatures and enjoy a moderate climate. This is because the interchange of sea and land breezes, caused by differential heating of land and sea, maintains the heat balance and cools the coastal regions or makes the sea cooler.

7. Why is India cooler in December than in July?

Answer: India is cooler in December than in July because of the tilt of the earth’s axis and its revolution around the sun. In December, the Northern Hemisphere is tilted away from the sun, so India receives less direct sunlight. The sun’s rays fall more slantingly, which means they spread over a larger area and travel a longer distance through the atmosphere, reducing their heating effect.

In contrast, during July, the Northern Hemisphere is tilted towards the sun. The sun’s rays fall more vertically over India, covering a smaller area and travelling a shorter distance through the atmosphere. This results in more intense heating, making July much hotter than December.

Distinguish Between

1. Distinguish between Insolation and Terrestrial Radiation.

Answer: Insolation is the amount of solar energy received by the earth. The sun’s energy reaches the earth as short wave rays.

Terrestrial Radiation occurs when solar radiation (insolation) strikes the surface of the earth. The surface of the earth radiates this heat back into the atmosphere in the form of long waves. The heat radiated by the earth in the form of long waves is called Terrestrial Radiation.

The key distinctions are:

Source: Insolation is energy from the sun received by the earth, while Terrestrial Radiation is heat radiated from the earth’s surface back into the atmosphere.
Wave Type: Insolation reaches the earth as short wave rays, while Terrestrial Radiation is in the form of long waves.

2. Distinguish between Land breeze and sea breeze.

Answer: Sea breeze and land breeze are caused by convection currents in the atmosphere and the differential heating and cooling of land and sea.

Sea Breeze: During the day, air over land becomes warmer and rises because the land gets hotter than the sea. Cool air from oceans (or surrounding seas) moves in to take its place. This cool breeze that blows over the earth from the surrounding seas towards the low pressure area over the land during the day is known as Sea Breeze. It lowers the temperature of the air on land and cools the coastal regions.

Land Breeze: In the night, the situation is the reverse. The sea remains warmer than the land because the land surface gets cooled more quickly than the ocean surface. The breeze that blows from land to sea in the night is known as land breeze. It makes the sea cooler.

The key distinctions are:

Timing: Sea breeze occurs during the day, while land breeze occurs during the night.
Direction of Flow: Sea breeze blows from the sea to the land, while land breeze blows from the land to the sea.
Cause: Sea breeze is caused by warmer air rising over the land creating low pressure, drawing cooler air from the sea. Land breeze is caused by the sea remaining warmer at night, with cooler, denser air from the land flowing towards the sea.

Effect: Sea breeze cools the coastal regions during the day. Land breeze makes the sea cooler during the night. The interchange of breeze maintains the heat balance.

Structured Questions

1. (a) How is ‘heat balance’ achieved?

Answer: There exists a state of equilibrium on earth between incoming insolation from the sun and the outgoing terrestrial radiation from the earth, known as Heat Balance. The balance of the heat budget is important for life to survive on the earth. Since the earth rotates on its axis, the sun’s rays do not warm all parts of the earth equally. This sets off several processes into motion and has an impact on the earth’s heat distribution. The heat radiated by the earth’s surface warms the layers of air above it by direct contact, which is called conduction. The circulation of air and water in oceans causes transfer of heat from one medium to another or from one level to another; this transfer of heat by circulatory movement is called convection.

The atmosphere plays a crucial role in achieving this balance. The atmosphere absorbs 34 units of the earth’s radiation, but it absorbs only 14 units of the sun’s incoming radiation. Thus, the atmosphere is heated more by terrestrial radiation given out by the earth than by the incoming insolation from the sun. The atmosphere acts like a blanket. At night, the atmosphere acts like a greenhouse and keeps the earth’s surface warm by preventing the terrestrial radiation from escaping into space. During the day, the atmosphere absorbs 14% of insolation and thus regulates temperature on earth. In this way, the atmosphere prevents extremes of temperatures, contributing to the heat balance.

(b) State how latitude affects the temperature of a place.

Answer: Temperature depends on the latitude of a place.

(i) Temperature decreases with increase in latitude on either side of the Equator due to the spherical shape of the earth and its annual revolution around the sun.
(ii) The sun’s rays strike the earth at varying angles of incidence owing to the spherical shape of the earth and its inclination on its axis. Oblique or slanting rays not only travel a longer distance, but also heat a larger area. Thus, they have less heating power. The midday sun is almost overhead within the tropics but at oblique angles outside the tropics. These factors indicate that higher the latitude, the colder is the place.

(c) Give a reason for each of the following:
(i) North India has a greater range of temperature than South India.

Answer: Areas close to the sea have lower daily and annual ranges of temperatures and enjoy a moderate climate than areas lying in the interior. South India, being largely peninsular and coastal, experiences this moderating influence of the sea. North India, being largely in the interior and away from the sea’s influence, experiences a greater range of temperature.

(ii) The temperature of Delhi is less than that of Chennai in December.

Answer: Temperature decreases with an increase in latitude on either side of the Equator. Delhi is located at a higher latitude than Chennai. Additionally, the sun’s rays which fall over the Torrid Zone, where Chennai is closer, travel a shorter distance and heat up a smaller surface area leading to higher temperature. Beyond the Torrid Zone, where Delhi is located further north, the sun’s rays travel a longer distance, fall in a slanting position, heat up a larger area, and thus temperature goes on falling. Therefore, in December, Delhi experiences lower temperatures than Chennai.

(iii) Desert areas experience a high day temperature and a much lower night temperature.

Answer: Land gets heated or cooled more quickly than water. Desert areas are predominantly land. During the day, the land heats up rapidly due to solar insolation. At night, especially when the sky is clear and the air is very dry, conditions often found in desert areas, the heat from the earth’s surface escapes rapidly back into space. This rapid heating during the day and rapid cooling at night results in desert areas experiencing a high day temperature and a much lower night temperature, leading to a high diurnal range of temperature.

(d) Draw a well labelled diagram to show the Heat Budget of the earth.

Answer: See Fig. 13.1 of Morning Star/Total Geography or click here.

2. (a) State the five temperature zones of the earth.

Answer: The earth is divided into 5 temperature zones. These are:

the Torrid Zone between the Tropics of Cancer and Capricorn;
the North Temperate Zone;
the South Temperate Zone;
and the two Frigid Zones.

(b) Explain the Normal Lapse Rate.

Answer: The rate of decrease of temperature with height is about 6°C per km above the sea level and is known as Normal Lapse Rate. This means that on climbing every 166 metres, there is a fall of 1°C in temperature. It is usually more in summer than in winter. This explains why it is cooler at the top of a mountain than at the bottom or why hill resorts in summer in tropical countries have a pleasant climate than the plains.

(c) Give a reason for each of the following:
(i) Distance from the sea affects the temperature of a place.

Answer: Distance from the sea affects the temperature of a place because land and water heat and cool at different rates. Sun’s rays pass through water to a great depth, and water being mobile, warm water mixes easily with cold water, so water is neither heated nor cooled quickly. However, the sun’s rays heat a piece of land more rapidly because the heat obtained remains confined to that area and does not mix with other areas of land. Hence, land gets heated or cooled more quickly than water.

During the day, land is hotter than the sea, and cooler sea breezes blow towards the land, lowering the land temperature. At night, the sea remains warmer than the land, and land breezes blow from land to sea. This interchange of breezes helps maintain a heat balance. Consequently, areas close to the sea have lower daily and annual ranges of temperatures and enjoy a moderate climate compared to areas lying in the interior, which experience greater temperature extremes.

(ii) Land is heated and cooled faster than the sea.

Answer: Land is heated and cooled faster than the sea because the sun’s rays heat a piece of land more rapidly as the heat obtained by the area remains confined to that area and does not mix with other areas of land. In contrast, sun’s rays pass through water to a great depth, water is mobile, and the warm water mixes easily with the cold water. Because of these reasons, water is neither heated nor cooled quickly, while land gets heated or cooled more quickly.

(iii) The ports of the western coast of Europe remain ice-free during winter.

Answer: The ports of the western coast of Europe remain ice-free during winter because the warm North Atlantic Drift raises the winter temperature of North-West Europe, especially those of the British Isles and Norway. Due to the influence of the Warm North Atlantic Drift, the port of Bergen (about 60°N) in Norway remains open during the winter season.

(d) Draw a well labelled diagram showing that the vertical rays are hotter than slanting rays.

Answer: See Fig. 13.5 of Morning Star/Total geography or click here.

3. (a) How does the distance from the sea affect the distribution of temperature?

Answer: Distance from the sea significantly affects the distribution of temperature. Land gets heated or cooled more quickly than water. Water bodies, like seas and oceans, heat up and cool down slowly. Therefore, coastal areas, being close to the sea, experience a moderating influence. During the day, the cooler air from the sea (sea breeze) blows towards the land, lowering the temperature. During the night, the land cools faster than the sea, and air blows from land to sea (land breeze). This interchange results in coastal areas having lower daily and annual ranges of temperatures and a more moderate climate. In contrast, areas in the interior, far from the sea’s influence, experience greater extremes of temperature, being much hotter in summer and colder in winter. Thus, proximity to the sea leads to a more equable temperature distribution, while distance from the sea leads to a continental type of temperature distribution with greater variations.

(b) How would the breezes that blow during the day and those that blow during the night affect the temperature of a place situated in the coastal region?

Answer: In a place situated in a coastal region, the breezes that blow during the day and night significantly affect its temperature.

During the day, the land heats up faster than the sea, causing the air over the land to become warmer, lighter, and rise, creating a low-pressure area. The air above the sea is cooler and denser. This cooler air blows from the sea towards the low-pressure area over the land; this is known as a sea breeze. The sea breeze lowers the temperature of the air on land, making the coastal region cooler during the day.

At night, the situation is reversed. The land cools down faster than the sea, so the sea remains warmer than the land. The breeze that blows from land to sea in the night is known as a land breeze. This makes the sea cooler near the coast.

Thus, the interchange of sea and land breezes maintains the heat balance and results in coastal regions having a moderate climate with lower temperature ranges.

(c) Give a reason for each of the following:
(i) Higher the latitude, lower is the temperature.

Answer: Higher the latitude, lower is the temperature primarily due to two factors. Firstly, temperature decreases with an increase in latitude on either side of the Equator because of the spherical shape of the earth and its annual revolution around the sun. Secondly, the sun’s rays strike the earth at varying angles of incidence. At higher latitudes, the sun’s rays are oblique or slanting. These slanting rays travel a longer distance through the atmosphere and heat up a larger surface area. Consequently, they have less heating power compared to the more direct rays received at lower latitudes.

(ii) The vertical rays of the sun give more insolation than the slanting rays.

Answer: Vertical rays of the sun give more insolation than slanting rays because vertical rays, such as those falling over the Torrid Zone, travel a shorter distance through the atmosphere and their energy is concentrated over a smaller surface area, leading to higher temperature and more intense heating. Slanting or oblique rays, which occur at higher latitudes, travel a longer distance through the atmosphere, and their energy is spread over a larger area. Thus, they have less heating power and deliver less solar energy per unit of area, meaning less insolation.

(iii) A desert region has a high range of temperature than a forest region.

Answer: A desert region has a high range of temperature because land gets heated or cooled more quickly than water, and deserts are predominantly dry land. During the day, the land heats up rapidly. Furthermore, in desert regions, the sky is often clear and the air very dry. Due to these conditions, the heat from the earth’s surface escapes rapidly back into space at night, leading to significant cooling. This rapid heating by day and rapid cooling by night results in a high diurnal range of temperature. Forest regions, in contrast, typically have more moisture in the air and ground due to vegetation and transpiration, and the canopy can reduce direct solar radiation reaching the ground and trap outgoing radiation, leading to a more moderated temperature range.

(d) Draw a well labelled diagram to show the land and sea breeze.

Answer: See Fig. 13.6. of Morning Star/Total geography or click here.

Thinking Skills

1. Solar radiation is the only primary source of light and heat on the earth. But only 51% of solar energy reaches the earth. What would happen if the entire solar energy reaches the earth? Give reasons to support your answer.

Answer: If the entire solar energy reached the earth, the planet would become extremely hot and uninhabitable. Currently, only 51% of solar radiation reaches the earth’s surface, while 35% is reflected back into space and 14% is absorbed by the atmosphere. This natural filtering helps maintain a balance in temperature. If all solar radiation reached the surface, it would disturb this balance, causing rapid heating. The atmosphere and surface would absorb too much energy, leading to extreme weather, melting of polar ice caps, and disruption of ecosystems. Life as we know it would not survive such conditions.

2. Do you think Greenhouse Gases affect earth’s heat budget? Give examples to support your answer.

Answer: Yes, greenhouse gases definitely affect the earth’s heat budget. They trap heat in the atmosphere by absorbing terrestrial radiation emitted by the earth’s surface. For instance, gases like carbon dioxide and water vapour prevent the heat from escaping into space at night, much like a greenhouse. This regulation keeps the surface warmer than it would be otherwise. Without these gases, the earth would lose too much heat, resulting in very cold temperatures at night and large temperature swings between day and night. Thus, greenhouse gases are crucial in maintaining a stable and liveable climate.

Extras

Additional MCQs

1. What is the continuous emission of heat and light energy from the sun known as?

A. Solar radiation
B. Insolation
C. Terrestrial radiation
D. Solar wind

Answer: A. Solar radiation

2. What term describes the amount of solar energy received by the Earth?

A. Insolation
B. Radiation balance
C. Terrestrial flux
D. Conduction

Answer: A. Insolation

3. What is the heat radiated by the Earth back into the atmosphere in the form of long waves called?

A. Convection
B. Solar wind
C. Terrestrial radiation
D. Insolation

Answer: C. Terrestrial radiation

4. What percentage of incoming solar energy is reflected back into space?

A. 35%
B. 14%
C. 51%
D. 48%

Answer: A. 35%

5. What percentage of incoming solar radiation is absorbed by atmospheric layers including ozone?

A. 14%
B. 34%
C. 35%
D. 17%

Answer: A. 14%

6. What percentage of incoming solar energy reaches the Earth’s surface?

A. 51%
B. 35%
C. 14%
D. 48%

Answer: A. 51%

7. What is the term for the state of equilibrium between incoming insolation and outgoing terrestrial radiation?

A. Heat balance
B. Thermal equilibrium
C. Radiation equilibrium
D. Energy budget

Answer: A. Heat balance

8. What term describes the flow of energy from the sun to the Earth and then into space by electromagnetic waves?

A. Conduction
B. Convection
C. Radiation
D. Reflection

Answer: C. Radiation

9. Which process transfers heat by circulatory movement of air and water?

A. Conduction
B. Convection
C. Radiation
D. Reflection

Answer: B. Convection

10. Which process transfers heat by direct contact?

A. Conduction
B. Convection
C. Radiation
D. Advection

Answer: A. Conduction

11. What phenomenon describes the cool airflow blowing from the sea to land during daytime?

A. Sea breeze
B. Land breeze
C. Monsoon
D. Trade wind

Answer: A. Sea breeze

12. What phenomenon occurs when cooler air from land moves toward the sea at night?

A. Land breeze
B. Sea breeze
C. Valley breeze
D. Mountain breeze

Answer: A. Land breeze

13. In which way does the atmosphere act at night to keep the Earth’s surface warm?

A. Like a greenhouse
B. Like a mirror
C. Like a conductor
D. Like a reflector

Answer: A. Like a greenhouse

14. What percentage of Earth’s longwave radiation is absorbed by the atmosphere?

A. 34%
B. 14%
C. 48%
D. 17%

Answer: A. 34%

15. What percentage of outgoing terrestrial radiation is emitted by the atmosphere?

A. 48%
B. 34%
C. 17%
D. 14%

Answer: A. 48%

16. What is the normal lapse rate of temperature decrease with altitude?

A. 6°C per km
B. 1°C per 100 m
C. 10°C per km
D. 2°C per 500 m

Answer: A. 6°C per km

17. On average, temperature falls by 1°C for every ascent of how many metres?

A. 166
B. 100
C. 200
D. 250

Answer: A. 166

18. Which of the following is not a factor affecting the distribution of temperature?

A. Rainfall
B. Latitude
C. Altitude
D. Slope

Answer: A. Rainfall

19. Temperature generally decreases with an increase in which geographical measurement?

A. Latitude
B. Longitude
C. Precipitation
D. Humidity

Answer: A. Latitude

20. Which type of solar rays covers a smaller surface area and has more heating power?

A. Vertical rays
B. Oblique rays
C. Reflected rays
D. Diffused rays

Answer: A. Vertical rays

21. Which latitudinal zone lies between the Tropic of Cancer and the Tropic of Capricorn?

A. Torrid zone
B. Temperate zone
C. Frigid zone
D. Monsoon zone

Answer: A. Torrid zone

22. Which zone lies between the Arctic Circle and the North Pole?

A. Frigid zone
B. Temperate zone
C. Torrid zone
D. Monsoon zone

Answer: A. Frigid zone

23. Sea breezes and land breezes are caused by temperature differences between which two surfaces?

A. Land and sea
B. Mountains and plains
C. Air masses
D. Deserts and forests

Answer: A. Land and sea

24. Areas close to the sea generally have what type of climate?

A. Moderate
B. Continental
C. Tropical
D. Desert

Answer: A. Moderate

25. Why does seawater heat and cool more slowly than land?

A. Mobility
B. Salinity
C. Albedo
D. Density

Answer: A. Mobility

26. Which component of solar radiation has the shortest wavelength?

A. Ultraviolet
B. Infrared
C. White light
D. Solar wind

Answer: A. Ultraviolet

27. Which component of solar radiation has wavelengths longer than visible light?

A. Infrared
B. Ultraviolet
C. White light
D. Solar wind

Answer: A. Infrared

28. Of the sun’s radiated energy, only one part out of how many reaches the Earth?

A. Two billion
B. Two million
C. Two trillion
D. Two hundred million

Answer: A. Two billion

29. What term describes the energy storage and transport in the atmosphere, hydrosphere and lithosphere?

A. Heat
B. Light
C. Radiation
D. Particles

Answer: A. Heat

30. Which topographical factor influences the amount of solar radiation a surface receives?

A. Slope
B. Altitude
C. Latitude
D. Ocean currents

Answer: A. Slope

31. Which slope orientation of an east-west aligned mountain range is generally warmer?

A. South-facing
B. North-facing
C. East-facing
D. West-facing

Answer: A. South-facing

32. Which factor affecting temperature distribution involves the movement of warm and cold ocean waters?

A. Winds and ocean currents
B. Latitude
C. Altitude
D. Slope

Answer: A. Winds and ocean currents

33. Which process leads to cooler temperatures in valleys compared to slopes on calm, clear nights?

A. Cold air sinking
B. Warm air rising
C. Convection
D. Conduction

Answer: A. Cold air sinking

34. Which ocean current raises winter temperatures of north-west Europe, keeping ports ice-free?

A. North Atlantic Drift
B. Labrador Current
C. Gulf Stream
D. Canary Current

Answer: A. North Atlantic Drift

35. Which cold ocean current keeps north-east Canadian ports frozen for several months?

A. Labrador Current
B. North Atlantic Drift
C. Gulf Stream
D. Benguela Current

Answer: A. Labrador Current

36. Which type of electromagnetic wave comprises terrestrial radiation?

A. Long waves
B. Short waves
C. Medium waves
D. Infrared

Answer: A. Long waves

37. What is the term for the rate at which temperature decreases with height above sea level?

A. Normal lapse rate
B. Temperature inversion
C. Heat budget
D. Radiation balance

Answer: A. Normal lapse rate

38. Which type of radiation heats the atmosphere more?

A. Terrestrial radiation
B. Incoming insolation
C. Solar wind
D. Conduction

Answer: A. Terrestrial radiation

39. Which component of solar radiation is visible to the human eye?

A. White light
B. Infrared
C. Ultraviolet
D. Solar wind

Answer: A. White light

40. What term describes the atomic particles emitted by the sun into space?

A. Solar wind
B. Solar radiation
C. Ultraviolet rays
D. Infrared rays

Answer: A. Solar wind

Additional Assertion and Reason

1. Assertion (A): Temperature decreases with increase in latitude on either side of the Equator.
Reason (R): This is due to the spherical shape of the earth and the varying angle of incidence of sun’s rays, causing slanting rays to travel a longer distance and heat a larger area.