Physical Geography (UPSC) (Part-III)

Total Questions: 44

41. Which of the following is/are correct inference/inferences from isothermal maps in the month of January? [2024-I]

The isotherms deviate to the north over the ocean and to the south over the continent.
The presence of cold ocean currents, Gulf Stream and North Atlantic Drift make the North Atlantic Ocean colder and the isotherms bend towards the north.

Select the answer using the code given below:

(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Correct Answer: (a) 1 only

Solution:The isotherms are generally parallel to the latitude. The deviation from this general trend is more pronounced in January than in July, especially in the northern hemisphere. In the northern hemisphere, the land surface area is much larger than the southern hemisphere. Hence, the effects of land mass and the ocean currents are well pronounced. In January the isotherms deviate to the north over the ocean and to the south over the continent. This can be seen on the North Atlantic Ocean. Thus, statement 1 is correct. The presence of warm ocean currents, Gulf Stream and North Atlantic drift, make the Northern Atlantic Ocean warmer and the isotherms bend towards the north. Over the land the temperature decreases sharply, and the isotherms bend towards south in Europe. Thus, statement 2 is incorrect. Hence, the correct answer is (a).

42. Consider the following statements: [2024-I]

Statement-I: Rainfall is one of the reasons for weathering of rocks.
Statement-II: Rainwater contains carbon dioxide in solution.
Statement-III: Rainwater contains atmospheric oxygen.

Which one of the following is correct in respect of the above statements?

(a) Both Statement-II and Statement-III are correct and both of them explain Statement-I
(b) Both Statement-II and Statement-III are correct, but only one of them explains Statement-I
(c) Only one of the Statements II and III is correct and that explains Statement-I
(d) Neither Statement-II nor Statement-III is correct

Correct Answer: (a) Both Statement-II and Statement-III are correct and both of them explain Statement-I

Solution:Weathering is the action of weather and climate elements on earth materials, divided into three major types: (i) chemical; (ii) physical or mechanical; and (iii) biological.
Chemical weathering processes break down rocks through chemical reactions involving oxygen, water (from rainfall), soil water, and other acids, reducing them to a fine clastic state. These reactions are accelerated by the presence of water, air (oxygen and carbon dioxide), and heat. Hence, Statement I is correct.
Normal rain has a pH of around 5.6, making it slightly acidic due to the dissolution of carbon dioxide (CO2) forming weak carbonic acid. Thus, Statement II is correct and supports Statement I.
As rain falls, it absorbs oxygen, leading to higher oxygen concentrations in the rain drops. Consequently, rainwater contains atmospheric oxygen. Thus, Statement III is correct. Therefore, rainfall provides water, CO2, and oxygen, which facilitate the chemical weathering of rocks. Thus, Statement II and Statement III are both correct and explain statement I.

43. Consider the following information: [2024-I]

Region	Name of the mountain range	Type of mountain
1. Central Asia	Vosges	Fold mountain
2. Europe	Alps	Block mountain
3. North America	Appalachians	Fold mountain
4. South America	Andes	Fold mountain

In how many of the above rows is the given information correctly matched?

(a) Only one
(b) Only two
(c) Only three
(d) All four

Correct Answer: (b) Only two

Solution:

Row 1 is incorrect: Block mountains form when large areas are broken and displaced vertically, with the uplifted sections known as horsts and the lowered sections called graben. The Vosges Mountain in Europe, rather than Central Asia, serves as an example of a block mountain system.
Row 2 is incorrect: The Alps, located in Europe, are among the youngest fold mountains, characterized by rugged relief and high conical peaks.
Row 3 is correct: The Appalachians in North America are among the oldest fold mountains in the world.
Row 4 is correct: The Andes, located in South America, are one of the youngest fold mountains.

44. Consider the following pairs: [2024-I]

Country	Animal found in its natural habitat
1. Brazil	Indri
2. Indonesia	Elk
3. Madagascar	Bonobo

How many of the pairs given above are correctly matched?

(a) Only one
(b) Only two
(c) All three
(d) None

Correct Answer: (d) None