Correct Answer:
(A)
Is a horizontal line to the sea level from where heights and depths are measured
The Datum line is a horizontal line from where all the elevations and depths are measured.
The most predominant datums types today are tidal datums and geodetic datums. Tidal datums are determined by averaging the level of water at a tide gage over time. Some simple examples of these are Mean Sea Level (MSL), Mean Low Water (MLW) and Mean Higher High Water (MHHW).
Ques:
102
The largest part of our hydrosphere is –
Correct Answer:
(C)
Pacific ocean
The area of given oceans is as follows – Pacific Ocean (165.2 million square kilometre), Atlantic Ocean (106.4 million square kilometre), Indian Ocean (73.6 million square kilometre), Antarctica Ocean (2.6-18.8 million square kilometre). Hence largest part of our hydrosphere is the Pacific Ocean.
Ques:
103
The tension of gravitational water in the ground is –
Correct Answer:
(A)
Below 1/3 atmosphere
Gravitational water occupies the larger soil pores (macro-pores) and moves down readily under the force of gravity. Gravitational water under the surface of soil remains in a state of zero or less than 1/3 of the atmosphere.
Ques:
104
Consider the following statements:
On the planet Earth, the fresh water available for use amounts to about less than 1% of the total water found.
Of the total freshwater found on the planet Earth, 95% is bound up in polar ice caps and glaciers.
Which of the statements given above is/are correct?
Correct Answer:
(A)
1 only
97% of the total water available on Earth is salt water found in Ocean. Out of the remaining 3% Fresh water, 2.4% is in the form of glaciers and polar ice, which is unusable for us. So, in this way total available fresh water to use is less than 1% of the total water available on earth. Out of total amount of fresh water (3%), 68.7% is found in the form of glaciers and polar ice, 30.1% in the form of underground water, 0.3% in the form of surface water and remaining 0.9% is found in other forms. Hence only statement (1) is correct.
Ques:
105
Which one is the most extensive part of the oceanic floor?
Correct Answer:
(D)
Deep Sea Plains
A most extensive part of the oceanic floor is 'Deep sea plain'. Characterized by flat and rolling submarine plain it is the most extensive relief zone of the ocean basins. These deep-sea plains having the depth of 3000 m to 6000 meters cover more than 76% percent of the total area of the Ocean Basins.