Question
With reference to agricultural soils, consider the
following statements: 1. A high content of organic matter in soil drastically reduces its water holding capacity 2. Soil does not play any role in the sulphur cycle 3. Irrigation over a period of time can contribute to the salinization of some agricultural lands Which of the statements given above is/are correct?Solution
Statements 1 and 2 are incorrect : Organic matter increases the water holding capacity of the soil. Sulphur cycle has both terrestrial as well as gaseous parts, Sulphur being stored as sulfates in soil. Statements 3 is correct : Irrigation over a long period of time can lead to salinization because irrigated water contains dissolved salts which get left behind when water evaporates. Over time, concentrations of those salts can reach levels that make it more difficult for plants to take up water from the soil.
A boat can travel 4.2km upstream in 14min. If the ratio of the speed of the boat in still water to the speed of the stream is 7:1. How much time will th...
Find the total distance covered by boat in each upstream and downstream in 6 hours if the speed of boat in still water and speed of current is 15 km/h a...
A man rows to a place 48 km distant and comes back in 14 hours. He finds that he can row 4 km with the stream at the same time as 3 km against the strea...
A boat takes 15 hours to go downstream from point 'I' to point 'J' and 25 hours to return upstream. The distance between 'I' and 'J' is 150 km. How long...
A man can row at a speed of 64 km/h in still water to a certain upstream point and back to the starting point in a river which flows at 8 km/h. Find his...
The boat's speed in still water is 20% greater than the speed of the stream. If it takes the boat 4 hours more to travel 176 km d...
Speed of a boat in still water is 15 kmph and speed of stream is 12 kmph. A man rows to a place at a distance of 54 km and come back to starting point. ...
Sumit can swim 12 km upstream and 16 km downstream in 5 hours. If ratio of speed of stream to that of speed of Sumit in upstream is 1:2, then find the s...
A boat can cover 72 km in still water and 60 km in downstream in 4 hours and 3 hours respectively. Find the time taken by the boat to cover 60 km upstre...
Speed of a boat in still water is 20 km/h while the speed of stream is ____ km/h. Total time taken by the boat to go 200 km upstream and 300 km downstre...