Question

Bholu took some top soil and mixed it with lots of water in a glass. He then allowed it to settle for a while. He found that many layers were formed. Starting from the bottom of the glass, choose the option which gives the correct sequence of soil layers.

• A. Humus→Clay→Sand→Gravel
• B. Gravel→Sand→Clay→Humus
• C. Sand→Gravel→Clay→Humus
• D. Gravel→Sand→Humus→Clay

Answer 1

The correct option is B

Gravel→Sand→Clay→Humus

Top soil contains particles made of sand, clay, gravel and humus. Gravel is large broken up stones or rocks that are present in the soil. Sand is made up of finer particles than gravel but, these particles are larger than clay particles. Humus is the lightest of all soil components and floats on top of the water.

Since heavier large particles sink deeper in water, the order starting from the bottom of the glass is Gravel $\to$ Sand $\to$ Clay $\to$Humus.