Soil Science - Study Mode
[#71] In plants, deficiency of Zn are usually associated with concentrations of less than . . . . . . . .
Correct Answer
(B) 20 ppm
Explanation
Solution: In plants, deficiency of Zn is usually associated with concentrations of less than 20 ppm. Zinc is a micronutrient element which means it is required in the least proportions by plants for their proper functioning. Deficiencies of Zn are observed with concentrations of less than 20 ppm. Its normal range is 25 - 150 ppm in plants. However, toxicities will occur when the Zn leaf concentration exceeds 400 ppm.
[#72] Bar is equal to
Correct Answer
(D) All of these
Explanation
Solution: The Bar is widely used in many countries as a unit of pressure. The bar is equal to 0.9869 atm. A standard atmosphere is abbreviated atm, also a unit of pressure equal to the average atmospheric pressure at sea level. The bar is equal to the weight of a 1020 cm water column. Inches of the water column is a measurement unit for measuring static pressure. The bar is equal to a 75.01 cm high mercury column. A milimetre of mercury is a manometric unit of pressure, it is defined as the extra pressure generated by a column of mercury one millimeter high. It is denoted as mmHg.
[#73] Strength of laboratory HCl is
Correct Answer
(A) 11 N
Explanation
Solution: 36.5 grams of hydrochloric acid is a 1 N (one Normal) solution of HCl. A normal is one gram equivalent of a solute per litre of solution. The strength of laboratory HCl is 11 N. In the context of acid and bases, it is generally assumed that N refers to the proton or the hydroxide ion released in water when acid is dissolved.
[#74] . . . . . . . . is the ratio of the increase in osmotic pressure produced by the fertilizer to that produced by the same weight of sodium nitrate (NaNO 3 )
Correct Answer
(D) Salt index
Explanation
Solution: The salt index is the ratio of the increase in osmotic pressure produced by the fertilizer to that produced by the same weight of sodium nitrate. It is calculated by comparing the increase in osmotic potential brought about by the addition of that fertilizer material compared to the increase in osmotic potential when an equivalent weight of sodium nitrate is added to water.
[#75] Near the canal banks soil become
Correct Answer
(A) Alkaline
Explanation
Solution: Near the canal banks, the soil becomes alkaline. These are largely predominant in the Indo-Gangetic plains encompassing most of the states of our country. Alkaline soils are rich in high amounts of calcium, sodium and magnesium. They are rich in high pH value. It has a poor soil structure and low infiltration capacity.