Question Discussion & Solution

After reading statement and conclusions we decide that -

i) All women are scientists.→ False 

ii) All scientists are women.→ False

Hence, option 4 is the correct answer.

Soil is one of the most important natural resources as mankind is dependent on soil for food. The soils of Rajasthan have developed under the arid and humid climate over the bedrocks of complex nature predominately through the process of Lateralization.

Classification: The old system of classification was developed by scientists (Thorpe & Smith) of the U.S Department of Agriculture in 1949. The classification is based upon differences in climate and mineralogy. As per this system, soils of Rajasthan can be classified into 8 types:

1. Desert Soils
2. Dunes and Associated Soils
3. Brown Soils
4. Sierozems
5. Red Loams
6. Hill Soils (Lithosols)
7. Saline Sodic Soils (Solonchaks)
8. Alluvial Soils/and Black Soils

Brown soil:

• Brown Soils Major area of these soils is in the catchment area of Banas River.
• Districts – Tonk, Bundi, Sawai Madhopur, Bhilwara, Udaipur, and Chittorgarh
• Annual Rainfall – 50 cm to 75 cm is sufficient for Kharif crops.
• Texture – Sandy loam to clay loam.
• Colour – Ranges from greyish brown to yellow-brown.
• They are rich in calcium salts but have poor organic matter
• The use of fertilizers becomes essential to get a good harvest
• As the groundwaters are saline, soils irrigate with these waters have accumulated salts
• Tank irrigated soils have also developed a problem of the high water table.
• Rabi crops are grown under irrigation.

Hence, option 1 is the correct answer.

In the fig. 1, in the top part of the plus, a curved arrow is placed and the adjacent triangle is filled. And at the bottom of the square, a callout is placed.

In the fig. 2, in the left part of the plus, a curved arrow is placed after rotating anticlockwise and the filled triangle is swapped. And in the right part of the plus, a callout is placed.

In the fig.3, in the bottom part of the plus, a curved arrow is placed after rotating anticlockwise and the filled triangle is swapped. And in the top part of the plus, a callout is placed.

In the fig.4, in the right part of the plus, a curved arrow is placed after rotating anticlockwise and the filled triangle is swapped. And in the left part of the plus, a callout is placed.

The correct answer is All of the above.

Key Points

• The major factors responsible for Desertification such as:
  • High temperature
  • High wind velocity.
  • Low vegetation.
  • High rainfall.
  • Overgrazing.
  • The exploitation of natural resources.
  • Soil pollution.
  • Climatic variability.

Additional Information

• The Thar desert is also known as The Great Indian Desert.
• It is spread over four states in India:
  • Punjab
  • Haryana
  • Gujarat
  • Rajasthan
• Thar Desert of Rajasthan, also known as the Great Indian Desert is a large arid region in the northwestern part of the Indian subcontinent and forms a natural boundary running along the border between India and Pakistan with an area of more than 100,000 km.
• It extends from the Sutlej river and is surrounded by the Aravali ranges on the east, on the south by the salt marsh known as the Great Rann of Kutch.
• The Annual Average rainfall is around 20-50mm.

CONCEPT:

Equilibrium of a rigid body:

• A rigid body is said to be in mechanical equilibrium if both its linear momentum and angular momentum are not changing with time, or equivalently, the body has neither linear acceleration nor angular acceleration.
• Condition for the mechanical equilibrium:
  1. The total force, i.e. the vector sum of the forces, on the rigid body is zero.
  2. The total torque, i.e. the vector sum of the torques on the rigid body is zero.

⇒ \(\rm\vec{F_1}+\vec{F_2}+...+\vec{F_n}=0\)

⇒ \(\rm \vec{τ_1}+\vec{τ_2}+...+\vec{τ_n}=0\)

• If the forces on a rigid body are acting in the 3 dimensions, then six independent conditions to be satisfied for the mechanical equilibrium of a rigid body.
• If all the forces acting on the body are coplanar, then we need only three conditions to be satisfied for mechanical equilibrium.
• A body may be in partial equilibrium, i.e., it may be in translational equilibrium and not in rotational equilibrium, or it may be in rotational equilibrium and not in translational equilibrium.

EXPLANATION:

• A rigid body is said to be in mechanical equilibrium if both its linear momentum and angular momentum are not changing with time, or equivalently, the body has neither linear acceleration nor angular acceleration.
• We know that the linear acceleration and the angular acceleration of a stationary body are zero.

A book is kept on a table:

• In this case, the book will be stationary so it is an example of the equilibrium of a body.

A ball is moving downward freely under gravity:

• We know that when a ball moves freely under gravity, then only the gravitational force will act on the ball due to which the ball accelerates downward.
• Therefore ball is moving downward freely under gravity is not an example of the equilibrium of a body.
• Hence, option 1 is correct.