Physical Geography (UPSC) (Part-I)

Total Questions: 50

1. A meteor is: [1995]

Correct Answer: (b) a piece of mater which has entered the earth's atmosphere from outer space
Solution:Meteor is a small celestial body which has entered the earth’s atmosphere by the gravitational force of earth, when they pass close to it. Meteors typically occurs in the mesosphere, and most range in altitude from 75 km to 100 km.
Meteor Showers
When a meteor shower occurs, through appropriate optical tools, the sky seems to be filled with fireworks. When there is a meteor shower, we can notice that all the meteor shower takes place from one point, and this point is known as the radiant point. Meteor showers are named after the constellation. The most commonly known meteor shower named after a constellation is the Leonid meteor shower. The shower appears to be falling from the constellation, but the source is the comet Tempel-Tuttle,

2. Which one of the following does not belong to biosphere reserves set-up so far? [1995]

Correct Answer: (d) Gulf of Kutch
Solution:Gulf of Kachchh has been declared a bio-sphere reserve in 2008.
There are 18 notified Bio-sphere reserves in India. Out of them, 12 Biosphere Reserves are in the UNESCO's MAB world Network.
• A Biosphere Reserve (BR) is an area of terrestrial, marine and coastal ecosystems that promote the conservation of biodiversity with its sustainable use.
• They are integral components of the internationally recognized framework of UNESCO’s Man and Biosphere (MAB) programme initiated in 1971 and they are nominated by national Governments.
• There are more than 500 such reserves spread across over 100 countries worldwide.

3. The graph given below shows the mean average monthly temperatures (in °C) and mean monthly rainfall (in cms) of a place: [1995]

This graph is indicative of which one of the climatic zones of the world?

Correct Answer: (a) Wet and dry tropical
Solution:In the graph the temperature ranges from 15° to 25°. So, the graph indicates wet and dry tropical region, and in this region rainfall does not exceed 25 cm.
The Savanna Climate, also known as the “Tropical Wet and Dry Climate” and “Sudan Climate”, is one of the most distinctive climatic regions of the world. It lies between the equatorial rainforest climate and the hot desert climate, forming a transitional zone. According to Köppen’s Climate Classification, it is denoted as “Aw type”. The savanna climate is characterized by distinct wet and dry seasons, with high temperatures throughout the year. It plays a vital role in shaping the ecology, agriculture, and livelihoods of millions of people across continents.

4. Willy Willy is: [1995]

Correct Answer: (c) a tropical cyclone of the North-west Australia
Solution:It is a tropical cyclone of north-west Australia. Willy Willy originates in the Timor sea and causes rainfall in different parts of Australia.
• Tropical Cyclone is a weather phenomenon.
• A tropical cyclone is formed only over warm ocean waters near the equator.
• Warm, moist air rises up and away from the ocean surface, creating an area of low pressure.
• It causes the air from surrounding areas with higher pressure to move towards the low-pressure area.
• This leads to warming up of air and causes it to rise above.
• As the air rises & cools, the water in the air forms clouds.
• This complete system of clouds and wind spins & grows, along with the ocean’s heat.
• As the wind rotation speed increases, an eye gets formed in the middle.

5. Which one of the following is the continent with the highest mean elevation in the world? [1995]

Correct Answer: (a) Antarctica
Solution:Antarctica is the highest continent on the planet with an average elevation of 7,545 feet above sea level. The elevation of Antarctica at the south pole is 9,300 feet.
• It is the southernmost continent and lies entirely within the Antarctic Circle spread around the South Pole.
• To the south of India, beyond the Indian Ocean lies the frozen continent of Antarctica.
• The name means – opposite the Arctic.
• It separated from the rest of the world by the icy waters of the Southern Ocean which comprises of the southern portions of the Indian, Atlantic, and Pacific Oceans.
• Its area is over 14 million square kilometers.
• It is the fifth-largest continent.
• It is larger than Europe and is twice the size of Australia.
• The continent is a high plateau that is frozen throughout the year.
• There is no coastal plain.

6. Which one of the following layers of the atmosphere is responsible for the deflection of radio waves? [1996]

Correct Answer: (d) Ionosphere
Solution:Ionosphere is the top layer of the atmosphere. Radio waves are deflected in the ionosphere of the atmosphere.
Ionosphere is composed of D, E and F layers. D layer (60 km from earth) is good at absorbing AM radio waves.
It is a part of Earth’s upper atmosphere, which is partially ionized extending from 100-1000km.
The ionosphere at polar regions is highly dynamic and acts as a major energy sink for space weather events, and related processes in magnetosphere-ionosphere systems as the magnetic field lines are vertical in this region.
It is an interesting layer which overlaps the mesosphere, thermosphere, and exosphere.
It’s a very active part of the atmosphere, and it grows and shrinks depending on the energy it absorbs from the sun.
The ionospheric observations in Antarctica are few compared to the Arctic region due to geographic limitations and limited number of stations.

7. Given below are two statements one labelled as Assertion (A) and the other labelled as Reason (R). [1996]

Assertion (A) : Areas near the equator receive rainfall throughout the year.

Reason (R) : High temperatures and high humidity cause convectional rain in most afternoons near the equator.

 

In the context of the above two statements, which one of the following is correct?

Correct Answer: (a) Both A and R are true and R is the correct explanation of A
Solution:

The assertion is correct and reason correctly explains the assertion because due to high temperature the atmospheric air gets heated and rises up. The daily cycle of heating, evaporation, and convection is common in the tropics of the equator.
It cools down and precipitates while the cool air descends down to take the place of the vacuum.

8. Given below are two statements, one labelled as Assertion (A) and the other labelled as Reason (R) : [1996]

Assertion (A) : Mangroves are very specialised forest eco-systems of tropical and sub-tropical regions bordering certain sea coasts.

 

Reason (R) : They stabilise the shoreline and act as bulwark against encroachments by the sea.

In the context of the above two statements, which one of the following is correct?

Correct Answer: (a) Both A and R are true and R is the correct explanation of A
Solution:Both the statements are correct and reason is correctly explained.
Mangroves are found in the bordering region of tropical and sub-tropical sea coasts. Mangroves stabilize the shoreline and act as a bulwark against sea erosion, which makes it a specialized forest ecosystem.
Mangrove is a type of tree species that grow in intertidal salty environments near the mouths of the delta of rivers along the coasts because they can tolerate frequent flooding and are able to obtain fresh water from rivers and also the nutrients required from salt water.
Features of Mangroves
• They are salt-tolerant plant species with roots dangling down into the water.
• Since they grow in very high salinity waters, they are adapted to the condition and are salt tolerant.
• They can secrete salt from their leaves to balance the salt intake.
• They have developed roots bearing pneumatophore (or aerial roots).
• These forests are also become quite resistant to high temperatures.
• They exhibit a viviparous mode of reproduction.

9. Diamond ring is a phenomenon observed: [1996]

Correct Answer: (c) only along the peripheral regions of the totality trail
Solution:• Total solar eclipses are among the most spectacular celestial events that can be observed from Earth. They occur when the Moon passes directly between the Sun and Earth, completely obscuring the Sun’s disk.
• One of the most breathtaking features of a total solar eclipse is the “diamond ring effect,” a phenomenon that occurs just before and just after totality.
• As the Moon moves across the face of the Sun, a point comes when only a single bright spot of sunlight remains visible, looking much like a shining diamond. This is surrounded by the faint glow of the Sun’s outer atmosphere, the corona, which appears like a ring. Hence, the name “diamond ring effect” aptly describes this stunning visual display.
• This phenomenon is also known as Bailey's Beads after English astronomer Francis Baily who discovered and explained this occurrence for the first time in 1836. According to Baily, the winking, diamond-like bursts of light were a result of the sun's rays squeezing through the valleys of the moon, leaving behind 'beads' of light on the edge of the moon's shape.

10. Which one of the following factors is responsible for the change in the regular direction of the ocean currents in the Indian Ocean? [1997]

Correct Answer: (b) Indian Ocean has monsoon drift
Solution:Due to the monsoon drift of the Indian Ocean, its regular direction of the ocean currents changes twice a year.
• Under the influence of prevailing trade winds (easterly trade winds), the north equatorial current and the south equatorial current start from the south of Indonesian islands, moving from east to west.
• This raises the level of western Indian (south-east of horn of Africa) ocean by few centimeters. And this creates a counter-equatorial current which flows between the north equatorial current and the south equatorial current in west-east direction.
• The north-east monsoons drive the water along the coast of Bay of Bengal to circulate in an anti-clockwise direction.
• Similarly, the water along the coast of Arabian Sea also circulate in an anti-clockwise circulation.