Class XI – Geography Paper – 3

Ans. (B) Both (A) and (R) are true and (R) is the correct explanation of (A)

Explanation: Due to the spherical shape of the earth the sun’s rays travel long distances to reach the poles and so little amount is received.

Ans. Option (A)

Explanation:

• Rajasthan is an Arid land due to which forest cover is less than 10% here.

• West Bengal has a forest area of 10-20% of its geographical area.

• Goa’s geographical area consists of 20-30% forest area

• 86.93% of the geographical area of Andaman and Nicobar Islands is covered with forest.

Ans. (B) spatial

Explanation: Geography helps in understanding reality in its spatial perspective by focusing on the spatial relationships, patterns, and interactions of various phenomena on Earth’s surface.

Ans. (B) Only statement I is true.

Explanation: Systematic approach was introduced by Alexander von Humboldt but it studies the world as a whole where identification of typologies or spatial patterns is done.

Ans. Option (B)

Explanation: The characteristic of Wave Amplitude- It is one-half of the wave height.

Ans. (B) Differentiation

Explanation: Differentiation is a process related to the internal structure of a planet and its layers, not directly connected to the formation or modification of the present atmosphere on Earth.

Ans. (B) south-central

Explanation: India is located in the south-central part of Asia.

Ans. (A) Sri Lanka

Explanation: Sri Lanka is an island country that is separated from India by Palk Strait and the Gulf of Mannar in the south of India.

Ans. (A) Nilgiri hills

Explanation: Dodabeta Peak is a part of the Western Ghats that is located in the Nilgiri hills.

Ans. (C) Both the statements are correct, and statement II correctly explains statement I

Explanation: Terrestrial planets are rocky because they were formed in the close vicinity of the parent star where it was too warm for gases to condense to solid particles.

Ans. (C) ii, iv, iii, i

Explanation: The longest river of the peninsular drainage system is Godavari also known as Dakshina Ganga, followed by River Krishna, Cauvery and Narmada.

Ans. (A) Chenab

Explanation: Chenab River is formed by two streams namely the Chandra and the Bhaga.

Ans. (D) Himalayan

Explanation: The Himalayan mountains are tectonic in origin, dissected by fast-flowing rivers which are in their youthful stage.

Ans. (A) 11° Channel

Explanation: 11° Channel separates the Andaman Islands from the Nicobar Islands.

Ans. (A) 1

Explanation: A large body of magmatic material that cools in the deeper depth of the crust develops in the form of large domes are Batholiths.

Ans. (A) Dykes

Explanation: When the lava makes its way through cracks and the fissures developed in the land, it solidifies almost perpendicular to the ground and this is known as Dykes.

Ans. (C) Batholiths

Explanation: Batholiths are known as a cooled portion of the magma chambers.

Ans. 103 national parks are there in the country.

Ans. In 1973, the Project Tiger was implemented.

Ans. The purpose of the Man and Biosphere Programme is to ensure the better conservation of flora and fauna.

Ans. Himalayas

Ans. Tropical forests occupy most of the geographical region.

Ans. The Gujarat state of India has only temperate type of forests according to the Map.

Ans. El Nino is a complex weather system that appears once every three to seven years, bringing drought, floods and other weather extremes to different parts of the world. The various features of El Nino are:

(i) The system involves oceanic and atmospheric phenomena with the appearance of warm currents off the coast of Peru in the Eastern Pacific and affects weather in many places including India.

(ii) El-Nino is merely an extension of the warm equatorial current which gets replaced temporarily by the cold Peruvian current or Humbolt current.

(iii) This current increases the temperature of water on the Peruvian coast by 10°C.

Ans. India gets a monsoon named as South-West Monsoon because:

(i) The low-pressure conditions by early June are powerful enough to attract the trade winds of the Southern Hemisphere coming from the Indian Ocean. These South-East trade winds cross the Equator and enter the Bay of Bengal and the Arabian Sea, only to be caught up in the air circulation over India.

(ii) Passing over the equatorial warm currents they bring with them moisture in abundance.

(iii) After crossing the Equator, they follow south- westerly directions and they are known as south-west monsoon.

Ans. The characteristics of the Peninsular River:

(i) The Peninsular drainage system is older than the Himalayan one. This is evident from the broad, largely-graded shallow valleys, and the maturity of the rivers.

(ii) The rivers originate in the peninsular plateau and central highlands. These are seasonal as they depend on monsoon rainfall.

(iii) They reflect the superimposed type of drainage pattern and are rejuvenated resulting in trellis, radial and rectangular patterns.

Ans. Yes, in my view India needs to have more than one standard time as India has a large longitudinal extent of about 30°.

(i) When the Sun is still shining on the western coast it is already night in the northeast so we need two or more time zones to clearly reflect day-to-day changes.

(ii) Time variation of 2 hours between the Easternmost and the Westernmost parts of our country. The Sun rises two hours earlier in Arunachal Pradesh as compared to Gujarat because the earth is tilted and also it rotates in East to Wests direction during rotation the Eastern part of the world experiences sun rays earlier as compared to the western parts of the world.

(iii) Other countries like the USA, Canada and Russia have more than one standard time because their longitudinal extend is large. India’s longitudinal extend is also 30°. Therefore, it is advisable to use more than one standard time.

Ans. The latitudinal spread of India is advantageous as:

(i) The Tropic of Cancer divides India into two parts. The southern part is in the tropical zone while the northern part is in the temperate zone.

(ii) It brings climatic diversity to India which has many advantages.

(iii) As we move from Kanyakumari to J&K, the duration of day and night decreases by more than 41⁄2 hours.

Ans. The ocean currents can be classified as-

On the basis of their depth:

(i) Surface currents: It constitutes about 10 per cent of all the water in the ocean, these waters are the upper 400 m of the ocean.

(ii) Deep water currents: It makes up the other 90 per cent of the ocean water. These waters move around the ocean basins due to variations in density and gravity. Deep waters sink into the deep ocean basins at high latitudes, where the temperatures are cold enough to cause the density to increase.

On the basis of temperature:

(i) Cold currents bring cold water into warm water areas. These currents are usually found on the west coast of the continents in the low and middle latitudes (true in both hemispheres) and on the east coast in the higher latitudes in the Northern Hemisphere.

(ii) Warm currents bring warm water into cold water areas and are usually observed on the east coast of continents in the low and middle latitudes (true in both hemispheres). In the Northern Hemisphere, they are found on the west coasts of continents in high latitudes.

Ans. The monsoon regime emphasises the unity of India with the rest of the Southeast Asian region. This view of broad unity of the monsoon type of climate should not, however, lead one to ignore its regional variations which differentiate the weather and climate of different regions of India. For example, the climate of Kerala and Tamil Nadu in the south are so different from that of Uttar Pradesh and Bihar in the north, and yet all of these have a monsoon type of climate.

While in the summer the mercury touches 55°C in western Rajasthan, it drops down to as low as minus 45°C in winter around Leh. Churu in Rajasthan may record a temperature of 50°C or more on a June day while the mercury hardly touches 19°C in Tawang (Arunachal Pradesh) on the same day. On a December night, the temperature in Drass (Jammu and Kashmir) may drop down to minus 45°C while Thiruvananthapuram or Chennai on the same night records 20°C or 22°C. These examples confirm that there are seasonal variations in temperature from place to place and from region to region in India.

Not only this, if we take only a single place and record the temperature for just one day, variations are no less striking. In Kerala and in the Andaman Islands, the difference between day and night temperatures may be hardly seven or eight degree Celsius. But in the Thar desert, if the day temperature is around 50°C, at night, it may drop down considerably upto 15°-20°C.

While snowfall occurs in the Himalayas, it only rains over the rest of the country. While Cherrapunji and Mawsynram in the Khasi Hills of Meghalaya receive rainfall of over 1,080 cm in a year, Jaisalmer in Rajasthan rarely gets more than 9 cm of rainfall during the same period.

Tura situated in the Garo Hills of Meghalaya may receive an amount of rainfall in a single day which is equal to 10 years of rainfall at Jaisalmer. While the annual precipitation is less than 10 cm in the northwest Himalayas and the western deserts, it exceeds 400 cm in Meghalaya.

The Ganga delta and the coastal plains of Orissa are hit by strong rain-bearing storms almost every third or fifth day in July and August while the Coromandel coast, a thousand km to the south, goes generally dry during these months. Most parts of the country get rainfall during June-September, but in the coastal areas of Tamil Nadu, it rains at the beginning of the winter season. In spite of these differences and variations, the climate of India is monsoonal in rhythm and character.

Ans. If the world misuses the river water, it will lead to a number of problems such as:

(i) No availability in sufficient quantity: The volume of river water will gradually start decreasing if we don’t make sensible use of the available river water. There will be no substitute left for the deficit of river water.

(ii) River water pollution: Dumping of solid wastes and litter in water bodies causes huge problems. Litters include plastic, aluminium, Styrofoam, etc. Different things take different amounts of time to degrade in water. They affect aquatic plants and animals and also pollute the river water.

(iii) River water disputes between states: There will arise river water disputes between many states. One such dispute witnessed in India is the Cauvery dispute between Karnataka and Tamil Nadu.

(iv) Sediment pollution: Misuse of river water will lead to siltation or sediment pollution. It refers to the increased concentration of suspended sediments on bottoms where they are undesired.

(v) Uneven seasonal flow of water: Due to misuse of river water, the sufficient quantity required for maintaining the flow of water will also decrease hence leading to an uneven seasonal flow of water.

Ans. The following are considered to be the stages in the development of planets:

(i) The stars are localised lumps of gas within a nebula. The gravitational force within the lumps leads to the formation of a core to the gas cloud and a huge rotating disc of gas and dust develops around the gas core.

(ii) In the next stage, the gas cloud starts getting condensed and the matter around the core develops into small-rounded objects.

(iii) These small-rounded objects by the process of cohesion develop into what are called planetesimals. Larger bodies start forming by collision, and gravitational attraction causes the material to stick together.

(iv) Planetesimals are a large number of smaller bodies.

(v) In the final stage, these large numbers of small planetesimals accrete to form fewer large bodies in the form of planets.

Ans. The most popular argument regarding the origin of the universe is the Big Bang Theory. It is also called the Expanding Universe Hypothesis. Edwin Hubble, in 1920, provided evidence that the universe is expanding. As time passes, galaxies move further and further apart. The universe appears to be growing larger. The Big Bang Theory considers the following stages in the development of the universe.

(i) In the beginning, all matter forming the universe existed in one place in the form of a “tiny ball” (singular atom) with an unimaginably small volume, infinite temperature and infinite density.

(ii) At the Big Bang the “tiny ball” exploded violently. This led to a huge expansion. It is now generally accepted that the event of the Big Bang took place 13.7 billion years before the present. The expansion continues even to the present day. As it grew, some energy was converted into matter. There was particularly rapid expansion within fractions of a second after the bang. Thereafter, the expansion has slowed down. Within the first three minutes of the Big Bang event, the first atom began to form.

(iii) Within 300,000 years from the Big Bang, the temperature dropped to 4,500 K and gave rise to atomic matter. The universe became transparent.

(iv) The expansion of the universe means an increase in space between the galaxies. An alternative to this was Hoyle’s concept of a steady state. It considered the universe to be roughly the same at any point in time.

(v) However, with greater evidence becoming available about the expanding universe, the scientific community at present favours the argument of expanding universe.

Ans. Erosion involves the acquisition and transportation of rock debris. When massive rocks break into smaller fragments through weathering and any other process, erosional geomorphic agents like running water, groundwater, glaciers, wind and waves remove and transport it to other places depending upon the dynamics of each of these agents. Abrasion by rock debris carried by these geomorphic agents also aids greatly in erosion. Weathering, mass-wasting and erosion are degradational processes. It is erosion that is largely responsible for continuous changes that the earth’s surface is undergoing. The work of the other two agents of erosion-waves and groundwater is not controlled by climate. In the case of waves, it is the location along the interface of the lithosphere and hydrosphere- coastal region – that will determine the work of waves, whereas the work of groundwater is determined more by the lithological character of the region.

Deposition is a consequence of erosion. The erosional agents lose their velocity and hence energy on gentler slopes and the materials carried by them start to settle themselves. The coarser materials get deposited first and finer ones later. By deposition, depressions get filled up. The same erosional agents viz., running water, glaciers, wind, waves and groundwater act as aggradational or depositional agents also.

Ans. Some of the landforms that are seen in the upper part of the river are:

(i) V-shaped valleys: Valleys start as small and narrow rills; the rills will gradually develop into long and wide gullies; the gullies will further deepen, widen and lengthen to give rise to valleys. Depending upon dimensions and shape, many types of valleys like V-shaped valleys, gorges, canyons, etc., can be recognised. (ii) Gorge: It is a deep valley with a very steep straight line. A gorge is almost equal in width at its top as well as its bottom. Gorges form in hard rocks.

(iii) Canyon: Canyon is characterised by steep step-like side slopes and may be as deep as a gorge. A canyon is wider at its top than at its bottom. In fact, a canyon is a variant of a gorge. Canyons commonly form in horizontal bedded sedimentary rocks.

(iv) Waterfall: When the rivers start falling in pits in mountainous regions, it makes a waterfall. Waterfalls also occur when meltwater drops over the edge of a tabular iceberg or ice shelf. (v) Plunge Pools: At the foot of waterfalls also, large potholes, quite deep and wide, form because of the sheer impact of water and rotation of boulders. Such large and deep holes at the base of waterfalls are called plunge pools. These pools also help in the deepening of valleys.

Ans. The atmosphere is composed of gases, water vapour and dust particles. The proportion of gases changes in the higher layers of the atmosphere in such a way that oxygen will be almost in negligible quantity at the height of 120 km.

Carbon dioxide is meteorologically a very important gas as it is transparent to incoming solar radiation but opaque to outgoing terrestrial radiation.

Ozone is another important component of the atmosphere found between 10 and 50 km above the earth’s surface and acts as a filter and absorbs the ultraviolet rays radiating from the sun and preventing them from reaching the surface of the earth.

Water vapour is also a variable gas in the atmosphere, which decreases with altitude. It also absorbs parts of the insolation from the sun and preserves the earth’s radiated heat. It thus, acts like a blanket allowing the earth neither to become too cold nor too hot.

Dust particles are generally concentrated in the lower layers of the atmosphere; yet, convectional air currents may transport them to great heights. Dust and salt particles act as hygroscopic nuclei around which water vapour condenses to produce clouds.

Ans. The heating and cooling mechanism of the atmosphere includes:

1. Conduction:

a. The earth after being heated by insolation transmits the heat to the atmospheric layers near the earth in long waves form. The air in contact with the land gets heated slowly and the upper layers in contact with the lower layers also get heated. This process is called conduction.

b. Conduction takes place when two bodies of unequal temperature are in contact with each other, there is a flow of energy from the warmer to the cooler body. The transfer of heat continues until both bodies attain the same temperature or the contact is broken. Conduction is important in heating the lower layers of the atmosphere.

2. Convection:

a. The air in contact with the earth rises vertically on heating in the form of currents and further transmits the heat of the atmosphere. This process of vertical heating of the atmosphere is known as convection.

b. The convective transfer of energy is confined only to the troposphere.

3. Advection:

a. The transfer of heat through the horizontal movement of air is called advection. The horizontal movement of the air is relatively more important than the vertical movement. In middle latitudes, most diurnal (day and night) variations in daily weather are caused by advection alone. b. In tropical regions particularly in northern India during the summer season local winds called ‘loo’ is the outcome of the advection process.

Ans. Kanchenjunga

Ans. Northern Plains

Ans. Gujarat

Ans. Andaman and Nicobar Islands

Ans. Mumbai port

Ans. Deccan Plateau

Ans. Assam – Majuli island

Ans.