Question

In the following questions a statement of Assertion (A) is followed by a statement of Reason (R). Identify and mark the correct choice. Assertion: Black soils are black in colour due to diffusion of iron in crystalline and metamorphic rocks. Reason: They develop deep cracks during hot weather. 

1- Both A and R are true and R is the correct explanation of A.

2- Both A and R are true and R is not the correct explanation of A.

3- A is true but B is false.

4- A is false but R is true.​

Answer 1

1.Both A and R are true and R is the correct explanation of A.

2.A is true but B is false.

Answer 2

The correct option is A is false but R is true.​

• Clay is abundant in black soil. It has a high water retention capacity since it is deep and resistant.
• Because of the presence of various elements such as iron, aluminum compounds, and humus, these soils retain black colour.
• When wet, they expand and become sticky, and when dry, they form deep broad fissures. This aids in self-aeration, which leads to nitrogen absorption from the atmosphere.