Physical Geography (UPSC) (Part-II)

Total Questions: 50

31. A geographic region has the following distinct characteristics: [2010]

  1. Warm and dry climate
  2. Mild and wet winter
  3. Evergreen Oak trees

The above features are distinct characteristics of which one of the following regions?

Correct Answer: (a) Mediterranean
Solution:Mediterrian climate have mild, rainy winter and hot, dry summers and Evergreen, Oak trees.
About the Mediterranean Climate
• The Mediterranean climate is characterized by hot, dry summers and mild, wet winters. This climate is primarily found around the Mediterranean Basin, but also occurs in regions like southern California, central Chile, parts of South Africa, and southwestern Australia.
• It is influenced by the subtropical high-pressure system, resulting in dry summers and wet winters.
• During the summer months, high-pressure systems dominate, bringing clear skies, high temperatures, and minimal rainfall. In contrast, the winter season is marked by lower pressure, which brings cooler temperatures and more precipitation.
• These seasonal variations contribute to the development of unique vegetation, such as olive trees, vineyards, and shrubs like chaparral and maquis.
• Mediterranean climates support diverse ecosystems, including rich biodiversity, fertile agricultural land, and scenic landscapes.
• However, due to its arid summers and seasonal rainfall, regions with a Mediterranean climate are susceptible to drought and wildfire risks, making sustainable land management essential for maintaining ecological balance.

32. What causes wind to deflect toward left in the Southern Hemisphere? [2010]

Correct Answer: (c) Rotation of the earth
Solution:Rotation of the earth causes wind to deflect towards left in the Southern Hemisphere.
Earth’s Rotation
• Day-Night Cycle: Earth’s rotation on its axis creates the day and night. While on one side of the Earth it is facing the Sun, the other side is in shadow and makes for night. The Earth takes roughly 24 hours to complete one rotation.
• Weather and Climate Formation: Rotation sets up wind patterns, the movement of ocean currents, and atmospheric circulation. The Coriolis force, which arises from the Earth’s rotation, causes these winds and currents to deflect and rotate in patterns in one direction in the Northern Hemisphere and the opposite way in the Southern Hemisphere, which in turn affects weather systems globally.
• Timekeeping: Timekeeping is based on the rotation of the Earth; this consists of 24 hours for a complete rotation. Each time zone deals with the position of Earth with respect to the Sun in the sky.

33. If a tropical rain forest is removed, it does not regenerate quickly as compared to a tropical deciduous forest. This is because [2011-I]

Correct Answer: (a) the soil of rain forest is deficient in nutrients
Solution:The soils of tropical rainforest are relatively poor in nutrients. Due to torrential rains most of the nutrients washed out of the soil and the soils contain less organic matter than the tropical deciduous forests.

Nutrients in the soil are often in forms that are not accessible by plants, unlike tropical deciduous forests where major nutrients remain in the soil. Thus if a tropical rain forest is removed it does not regenerate quickly as compared to a tropical deciduous forest.

34. A layer in the Earth’s atmosphere called ionosphere facilitates radio communication. Why? [2011-I]

  1. The presence of ozone causes the reflection of radio waves to earth.
  2. Radio waves have a very long wavelength.

Which of the statements given above is/are correct?

Correct Answer: (d) Neither 1 nor 2
Solution:Statement 2 is not supportive. Statement 1 is wrong, ionosphere contains charged particles due to which electromagnetic radio waves gets reflected and communication becomes possible. Ozone is found mainly in stratosphere and in traces in troposphere. Its main function is absorption of UV rays.

While the ions give the ionosphere its name, it is the free electrons that effect the radio waves and radio communications. Also Radio waves have the longest wave length in the EM spectrum.

35. La Nina is suspected to have caused recent floods in Australia. How is La Nina different from El Nino? [2011-I]

  1. La Nina is characterized by unusually cold ocean temperature in equatorial Indian Ocean whereas El Nino is characterized by unusually warm ocean temperature in the equatorial Pacific Ocean.
  2. El Nino has adverse effect on south-west monsoon of India, but La Nina has no effect on monsoon climate.

Which of the statements given above is/are correct?

Correct Answer: (d) Neither 1 nor 2
Solution:

Difference between El Nino and La Nina

El Nino La Nina
It accompanies high air surface pressure in the western Pacific.It accompanies low air surface pressure in the eastern Pacific.
El Nino occurs when tropical Pacific Ocean trade winds die out, and ocean temperatures become unusually warm.La Nina occurs when the trade winds blow unusually hard, and the sea temperatures become colder than normal.
El Nino is the warming of the Pacific Ocean between South America and the Date Line.La Nina occurs when the trade winds blow unusually hard, and the sea temperatures become colder than normal.

36. What is the difference between asteroids and comets? [2011-I]

  1. Asteroids are small rocky planetoids, while comets are formed of frozen gases held together by rocky and metallic material.
  2. Asteroids are found mostly between the orbits of Jupiter and Mars, while comets are found mostly between Venus and Mercury.
  3. Comets show a perceptible glowing tail, while asteroids do not.

Which of the statements given above is/are correct?

Correct Answer: (b) 1 & 3 only
Solution:Comets found beyond Nepture i.e. Kupier belt. Asteroids are tiny planetary bodies revolving around the sun between the orbits of Jupiter and Mars. While comets are mode up of small icy particles and Neteoric fragments.
  • Asteroids are remnants of planetary formation that failed to coalesce because of the gravitational interference of Jupiter. They circle the Sun in a zone lying between Mars and Jupiter. The circular chain of asteroids is called the asteroid belt. It lies between 2.3 and 3.3 AU from the Sun.
  • Asteroids (planetoids — another term for an asteroid) are composed mainly of refractory rocky and metallic minerals, with some ice. They range in size from hundreds of kilometres across to microscopic.
  • Comets are icy frozen gases (water, ammonia, methane and carbon dioxide) which hold together small pieces of rocky and metallic minerals. They have highly elliptical orbits, unlike the planets which have near-circular orbits.
  • Short-period comets, with an orbital period of a few hundred years, originate in the Kuiper belt. Longer period comets, with orbits of thousands of years, come from the more distant Oort Cloud.
  • Oort Cloud is a giant shell of icy bodies that encircle the solar system occupying space at a distance between 5,000 and 100,000 AU.
  • When passing close to the Sun, comets heat up due to the effects of the solar wind upon the nucleus and begins to outgas, displaying a visible atmosphere or coma, and sometimes also a tail.

37. Westerlies in southern hemisphere are stronger and persistent than in northern hemisphere. Why? [2011-I]

  1. Southern hemisphere has less landmass as compared to northern hemisphere.
  2. Coriolis force is higher in southern hemisphere as compared to northern hemisphere.

Which of the statements given above is/are correct?

Correct Answer: (a) 1 only
Solution:The speed of these winds are higher and persistence in southern hemisphere. The land mass in southern hemisphere is lesser in comparison to northern hemisphere. As these winds crosses the landmass its velocity decreases. Thus the effect of westerlies is less over northern hemisphere than in southern hemisphere.

Properties of Westerlies

• The westerlies blow between 40° and 65° South latitudes.
• These latitudes are referred to as the Roaring Forties, Furious Fifties, and Shrieking Sixties by sailors.
• They blow towards the poles in the middle latitudes between 30 and 60 degrees latitude.
• They develop in high-pressure regions in the horse latitudes and move towards the poles, and guide extratropical cyclones in this direction.
• In the Northern Hemisphere, the winds are mostly from the southwest, while in the Southern Hemisphere, the winds are predominantly from the northwest.

38. What could be the main reason/reasons for the formation of African and Eurasian desert belt? [2011-I]

  1. It is located in the sub-tropical high pressure cells.
  2. It is under the influence of warm ocean currents.

Which of the statements given above is/are correct in this context?

Correct Answer: (a) 1 only
Solution:It is under the influence of cold ocean current. So given second statement is wrong.
Ocean currents are persistent and predictable flows of ocean water mass. These are driven by factors like wind, density gradients, Earth’s rotation, and landmasses that cause and influence their speed, direction and behaviour.
These horizontal and vertical movements of ocean water are part of a large complex system that regulates heat transfer, shapes biodiversity patterns, and plays a vital role in Earth's climate dynamics. Primarily, there are two types of ocean currents - warm and cold currents. These currents arrange themselves in such a way that they form the world’s major and minor oceanic gyres.

39. The jet aircrafts fly very easily and smoothly in the lower stratosphere. What could be the appropriate explanation? [2011-I]

  1. There are no clouds or water vapour in the lower stratosphere.
  2. There are no vertical winds in the lower stratosphere.

Which of the statements given above is/are correct in this context?

Correct Answer: (c) Both 1 and 2
Solution:Jet fly in the lower stratoshpere to avoid the turbulence. There are no clouds and the air is dry with little water vapour. There are no vertical winds in the lower strato-sphere.

About Stratosphere
The stratosphere rises to a height of 50 km, above the tropopause.

  • It contains the ozone layer which absorbs ultraviolet radiation and shields life on the earth from intense, harmful forms of energy.
  • Temperature in the stratosphere increases with altitude as a result of heat that is produced during the formation of ozone.
  • There is almost no water vapour in the stratosphere.
  • Although the stratosphere is nearly cloudy and weather-free, polar stratospheric clouds can occasionally be found at its lowest, coldest altitudes.
  • It’s the highest point in the atmosphere that jet planes can access.
  • The top of the stratosphere is called the stratopause.

40. Which of the following is/are cited by the scientists as evidence/evidences for the continued expansion of universe? [2012-I]

  1. Detection of microwaves in space
  2. Observation of redshift phenomenon in space
  3. Movement of asteroids in space
  4. Occurrence of supernova explosions in space

Select the correct answer using the codes given below:

Correct Answer: (a) 1 and 2
Solution:The cosmic microwave background (CMB) is the thermal radiation left over from the "Big Bang".

The CMB is well explained as radiation left over from an early stage in the development of the universe and its discovery is considered a landmarks test of the Big Bang model of the universe.

Red shift and Blueshift describes how light changes as objects in space (such as stars or galaxies) move closer or farther away from us. The concept is key to charting the universe's expansion.