Test: Physical Geography - 1 (2019 - 2013)

The favorable weather elements for dew include clear skies, light wind, decent soil moisture. Clear skies allow for the maximum release of longwave radiation to space.
Cloudy skies will reflect and absorb while remitting longwave radiation back to the surface and that prevents as much cooling from occurring. So B is the most appropriate reason.

As per the NASA webpage:

• Large amounts of methane are frozen in Arctic tundra soils and in marine sediments including gas hydrates. As Earth's climate warms, that methane is vulnerable to possible release into the atmosphere, where it can add to global warming. So 1 and 2 are correct.
• In Methane Cycle, every molecule of methane that goes into the atmosphere remains there for 8 years until it is removed by oxidation into carbon dioxide (CO₂) and water (H₂O). So, 3 is also correct.

• On 21st June, the Northern Hemisphere is tilted towards the sun. The rays of the sun fall directly on the Tropic of Cancer. So, (c) and (d) are wrong.
• Places beyond the Arctic Circle experience continuous daylight for about six months. So (a) is correct.

• On the scale of a million years, the earth's magnetic fields has been found to reverse its direction. So, first statement is right.
• There are three stages in the evolution of the present atmosphere....The early atmosphere largely contained water vapour, nitrogen, carbon dioxide, methane, ammonia and very little of free oxygen. There was no atmosphere on early earth. Water vapour, methane, carbon dioxide and ammonia released from molten mass covered the surface. So, CO₂ was present, So, 2 wrong.
• Early atmosphere of earth had no free oxygen, the (life) forms until then could at best be only "anaerobic". Chlorophyll-bearing organisms later released free oxygen which gave greater possibilities for life to evolve. The first non-cellular forms of life could have originated 3 billion years back....(then) About 2000 million years ago the first cellular forms of life appeared on earth. Some of these cells had the ability to release Oxygen. It means early atmosphere of the earth was (mainly) modified by solar winds. When living organisms originated, it was beyond their capacity to modify the early atmosphere, since
  they couldn't synthesize oxygen at that time. This eliminates Statement 3, Thus we are left with answer "A: Only 1".

Studies have shown that increased concentrations of carbon dioxide increase photosynthesis, spurring plant growth...Results showed that carbon dioxide fertilization explains 70 percent of the greening effect [NASA 2016]

Sand Mining wrecks the intertidal area and creates the imminent danger of saline water ingress into fresh water." Meaning salinity will increase, so statement 1 is wrong, by elimination we've answer (b) 2 and 3 only. In this question, first statement is wrong, and you've to identify right statements. So in real exam stress, some students may have made error of reading / ticking, and they'd have ticked the wrong option A: only 1. (you're right that it's wrong statement, but you're not asked to tick the wrong one.) So, be mindful of ticking in OMR.

The process of decay, added by bacterial action, transforms organic matter into humus. Humus enhances water retention capacity of the soil. So, 1 is wrong. By elimination we are left with Answer (b): 3 only.

Barren Island volcano became active again in March, 1991. A second phase of eruptions started in 1995. So it means third statement is wrong, by elimination, we've the answer (a) only 1.

• The Hindu: Indian Ocean Dipole (IOD) is an event which the western Indian Ocean becomes alternately warmer and then colder than the eastern part of the Indian ocean. So first statement is wrong.
• A positive IOD leads to greater monsoon rainfall and more active (above normal rainfall) monsoon
  days while negative IOD leads to less rainfall and more monsoon break days (no rainfall). So
  yes, IOD can influence El Nino's impact on Monsoon. So second statement is right.

The Brahmaputra enters India in the state of Arunachal Pradesh from its original source Tibet, and is joined by the Dibang River and the Lohit River at the head of the Assam Valley. It is joined in Sonitpur by the Kameng River (or Jia Bhoreli).
Brahmaputra’s main left bank tributaries, viz., Dibang or Sikang and Lohit. The important right bank tributaries are the Subansiri, Kameng, Manas and Sankosh. Therefore, all 3 correct.

The Earth's rotation on its axis explains the eastward flow of the equatorial counter-current. If the earth would have been rotating east to west, the piled up water would have come down on the west side. Therefore, essentially it's the earth's rotation that explains the eastward flow of equatorial counter current.

One of the main factors that is responsible for origin of tropical cyclones include Large sea surface with temperature higher than 27°C. But in the South Atlantic and South-Eastern Pacific regions the sea surface temperatures are not enough to form a tropical cyclone formation due to its tendency to remain relatively cooler and this dominates over other factors and prevent any cyclone origination in the region.

The passage points out equatorial region.

Tides are the rise and fall of sea levels caused by the combined effects of gravitational forces exerted by the Moon, Sun, and rotation of the Earth.

The Westerlies are prevailing winds from the west toward the east in the middle latitudes between 30 and 60 degrees latitude. They originate from the high-pressure areas in the horse latitudes and tend towards the poles and steer extra tropical cyclones in this general manner. The moist air masses that cause winter rains in North-Western region of India are part of westerlies.

Continental Drift has affected the evolution of animals, the world's geographical positions and the world's climates. The split of the original super land mass Pangea into Gondwanaland and the laurasia created new geographical/ climatic regions. The rearrangement and displacement of huge landmasses has helped create the diversity which we see in modern day species.
The final stages of evolution of Genus Homo occurs in the last 3 glacial cycles.

The central Asian steppes run through Kazakhstan, Turkmenistan, Uzbekistan and Mongolia. The climate here is harsh with dust storms, little to no rainfall and temperature ranging from – 4 to 50 degree Celsius.

The first statement is correct. One major factor affecting the distribution of the temperature of Earth is distribution of Land and Oceans. Since there  is  more land  in  Northern Hemisphere and more waters in Southern hemisphere and there is a big difference between the specific heat of land and water; the loss of heat from the continents is bigger than the oceans.
The continents get heated faster and get cooled faster in comparison to the oceans. This is the reason that the temperatures of the Oceans are moderate while that of continents is extreme. The moderating effect on temperature of the land due to proximity of the seas is called Maritime influence. The increasing effect on temperature of the land at interior of the continents is called Continental Influence.

The canopy is the primary layer of the forest forming a roof over the two remaining layers. The densest of the biodiversity is found here along with a large variety of epiphytes.

The mixing of warm and cold current in the region where planktons are found, is food for fishes. The temperature is just right for them to survive.
The temperature is just right for the growth of fish food called planktons.