11. Which one of the following stands for the symbol pH ?

1. 1. Phosphorus and hydrogen content in soil

   
   
   

   2. Percentage of hydrogen in soil

   
   
   

   3. Proportion of potash and hydrogen in soil

   
   
   

   4. Concentration of hydrogen ions in the soil

   
   
   

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   NA

   Correct Option: D

   NA

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12. Consider the following statements
    1. Chernozem soils originate under tall grass prairie vegetation.
    2. Literites form under hot and humid climatic conditions.
    Which of the statement (s) given above is / are correct ?

1. 1. 1 only

   
   
   

   2. 2 only

   
   
   

   3. Both 1 and 2

   
   
   

   4. Neither 1 nor 2

   
   
   

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   NA

   Correct Option: B

   NA

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13. Consider the following statements
    1. Laterite consists essentially of oxides of iron and aluminium.
    2. Ferrallitic soils occur widely in the humid tropics where chemical weathering and leaching are intense.
    Which of the statement (s) given above is / are correct ?

1. 1. 1 only

   
   
   

   2. 2 only

   
   
   

   3. Both 1 and 2

   
   
   

   4. Neither 1 nor 2

   
   
   

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   NA

   Correct Option: C

   NA

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14. Assertion (A) : Laterite soils are reddish in colour and poor in humus and plant nutrients.
    Reason (R) : In humid tropical climate, excessive leaching takes place under alternative arid and humid conditions.
    Code.

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

   
   
   

   2. Both (A) and (R) are true but (R) is not the correct explanation of (A)
      

   
   
   

   3. (A) is true but (R) is false
      

   
   
   

   4. (A) is false but (R) is true
      

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: A

   NA

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15. Consider the following statements
    Low soil fertility in Rainy Tropics can be caused by
    1. high temperature and heavy rainfall.
    2. eluviations and leaching.
    3. the existence of an extremely active bacterial life on the forest floor.
    Of these statements
    

1. 1. 1, 2 and 3 are correct

   
   
   

   2. 1 and 2 are correct

   
   
   

   3. 2 and 3 are correct

   
   
   

   4. 1 and 3 are correct

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: B

   NA

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