Specimen Paper

The lines of longitudes are called Meridians of Longitude because the word 'meridian' means "midday" and all the places on the same meridian have their noon at the same time.

(i) The axis on which earth rotates makes an angle of 66 1⁄2° with the plane of ecliptic and is tilted 23 1⁄2° from a line perpendicular to that plane. This tilt of earth is called inclination of the Earth's axis.

(ii) The Earth's axis is inclined at 23 1⁄2°.

1. Exfoliation — Exfoliation is the weathering process by which concentric shells, slabs, sheets, or flakes are successively broken loose and stripped away from a rock mass. This kind of weathering is also known as Onion Peeling.

2. Oxidation — The process by which oxygen present in air and water react with minerals in the rock is called oxidation. For example, most rocks contain a certain amount of iron. Oxygen and water react with iron to form iron oxide which easily erodes in comparison to iron. As it is removed the rocks are weakened and thus decomposed.

(i) Jet streams are fast flowing narrow air currents found in the upper atmosphere or in troposphere of some planets including earth. The main jet streams are located near the altitude of the tropopause.

(ii) Jet streams are important in aviation. By using jet streams, aviation fuel and flight time is saved.

Below diagram shows Orographic rainfall:

(i) Sources of soil pollution are:

1. Industrial waste — Industrial waste containing chemicals, when dumped in soil, causes soil pollution. For example, fly ash from thermal plants, chemicals from oil refineries pollute the soil.
2. Urban commercial and domestic waste — Non-biodegradable wastes like glass, plastic, polythene bags etc, either remain in the soil and take a long time to decompose.

(ii) Chemical fertilizers destroy the soil's natural balance. It makes the soil vulnerable to erosion, leaves it lacking in nutrients and starts a vicious cycle in which more fertilizers must be used to make up for nutrient depletion in soil. Also, the toxic chemicals may enter the food chain and lead to biomagnification.

1. Taiga region is situated between 55°N to 70°N latitudes. In Southern Hemisphere, there is no landmass between 55° to 70°. Therefore, the Taiga region does not exist in the southern hemisphere.

2. Prairies are called the granaries of the world because most of the wheat produced in USA and Canada comes from this region.

The Earth rotates on its axis from west to east. This rotation is the cause of a deflective force known as Coriolis Force which deflects the general direction of the ocean currents. For example, the currents flowing from Equator towards the North and South Poles are deflected to their right in the Northern Hemisphere and towards their left in the Southern Hemisphere.

(i) A deflective force that, as a result of the earth's rotation, deflects moving objects to the right in the northern hemisphere and in the left in the southern hemisphere is called coriolis force. This deflective effect of coriolis force is called coriolis effect. It affects the movement of ocean currents and winds.

(ii) The planetary winds do not blow straight from the low pressure belt to high pressure belt but their direction is affected by coriolis force. For example, trade winds in Southern Hemisphere do not blow from south to north but they blow from south-east to north-west.

(i) Latitudes are known as parallels of latitude as each of them is an imaginary circle parallel to the Equator and centered on the polar axis.

(ii) All longitudes join the two poles. Therefore, they are of same length.

Two effects of the rotation of the earth are:

1. Occurrence of day and night
2. Ocean currents and winds are deflected towards right in the Northern Hemisphere and towards the left in the Southern Hemisphere.

1. The shortest routes between two places is not the parallel latitudes but the arc of Great Circle as the arc is shortest distance between two points on the circle.
2. The Earth is a habitable planet because it has water and atmosphere(oxygen). The atmosphere keeps the earth warm and maintains the temperature of the earth.
3. Kuala Lumpur is situated near the Equator and London is situated on higher latitudes. The speed of rotation at Kuala Lumpur is much faster than that at London because as the latitude increases the speed of rotation decreases.

Below diagram shows Summer Solstice in the Northern Hemisphere:

The earth's crust consists of two layers - SIAL and SIMA.

The material of the upper or continental part of the earth's crust, characterized by relatively low density is called the SIAL layer.The SIAL layer has predominance of Silica and Aluminium. It is also known as granite layer which floats on SIMA.

The lower layer of the earth's outer crust that underlies the SIAL is SIMA layer. It consists of Silica and Magnesium and it is also known as basaltic layer.

(i) Difference between intermontane plateau and volcanic plateau:

(ii) Sierra in Spain is an example of residual mountain and Northern plains of India is an example of depositional plain.

Below diagram shows the rock cycle:

1. Igneous rocks are also called primary rocks because they are formed when molten lava solidifies. Sedimentary rocks and metamorphic rocks are formed from other rocks.
2. Sedimentary rocks which are organically formed consist of remains or forms of sea plants and animals which have been buried and preserved in these rocks for a long time. They may have fossils trapped in their layers while formation of sedimentary rocks.
3. The core of the Earth is in a semi—solid state because of extreme pressure which is 3 million tonnes greater at core than at the surface.

Two types of volcanoes are:

1. Active volcanoes — They constantly eject lava, gases and ash. For example- Sabancaya in Peru.
2. Dormant volcanoes — They remain dormant but can suddenly erupt and again go dormant. For example- The Vesuvius volcano in Italy.

1. Epicentre — The point of earth's surface directly above the focus of an earthquake is called epicentre.
2. Focus — The point of origin of earthquake, deep below the surface of earth is called Focus.

1. The volcanoes and earthquakes are associated with each other. Both occur along the faults between the tectonic plates. Therefore, belt of their occurrence is same.
2. When a river flows through a rocky area, and carries very little load because of the steep terrain, it forms a narrow opening at its mouth which gradually widens out into the sea. Such rivers do not form delta.
3. Chemical weathering is more common in the tropical regions because the climate of tropical region is hot and humid. High temperature and presence of moisture increases the rate of reaction thereby increasing the rate of chemical weathering.

1. Deflation hollow — The wind lowers the ground by blowing away the unconsolidated materials giving rise to large depressions called deflation hollow.
2. River meander — S-shaped loops formed in the middle course of the river in plains are called meanders. When the river moves slowly, it bends on a flat surface and swings outward to form larger meanders.
3. Block disintegration — It is a type of weathering in which rocks split along the joints into large rectangular shaped blocks. It occurs in well-jointed rock such as granite due to temperature change. It is partially effective in areas with great diurnal range of temperature (10°C to 15°C or more) and barren rocks without a protective vegetation cover.

Four factors that affect the movement of ocean current are:

1. Variation in Sea Water Temperature
2. Variation in Sea water Salinity
3. Configuration of Coastline
4. Planetary winds

Spring Tide

Neap Tide

1. Newfoundland, where Gulf stream (warm) and Labrador (cold) currents meet has rich fishing ground, because the mixing of the cold and warm currents provides ideal temperature conditions for the life of fish.
2. The eastern coast of Japan is warm even in January because of warm Kuroshio Current. It is the most important warm current of North Pacific Ocean. It's average temperature remains 18°C.
3. The tidal range differs from one water body to the other. In the open oceans such as Atlantic, tides flow and ebb regularly twice a day. The difference in height between high and low tides, may be only a half metre, but in shallow marginal sea, it can increase upto 10 metres. In the enclosed seas or sheltered seas such as Mediterranean or Baltic, the range may be very small.

Three ways in which oceans are important to us are:

1. They regulate our climate.
2. They provide most of the oxygen.
3. They provide food in the form of fish and other sea foods.

At higher latitude, the sun rays have to cover more distance to reach the earth's surface due to spherical shape of earth. Thus, they lose more heat as compared to the lower latitudes which receive direct rays of the sun. For example, the area around equator (0°) is hot and humid while the areas near arctic circle (66 1/2°) is cold throughout the year.

(i) The causes of destruction of ozone layer are:

1. Emission of Nitrogen Oxide by a large number of supersonic transport aeroplanes causes deterioration of ozone layer.
2. Release of synthetic chemicals primarily Chlorofluoro-carbons(CFCs) into the atmosphere is the most important cause of depletion of ozone layer.

(ii) Following are the impacts of ozone depletion on human life:

1. It will allow excessive radiation of ultraviolet rays which can render man and animal blind.
2. It can cause crop damage,
3. It can burn skin and cause cancer.

1. The Himalayan area near Tibet are situated on higher latitudes as compared to the Himalayas of Nepal. The temperature decreases with increase in latitudes. Therefore, the snow on the slope of Himalayas in Nepal melts faster than that on the slope towards Tibet.

2. Tropical deserts are free of cloud cover. This results in their quick heating as well as quick cooling due to radiation of heat. Therefore, tropical deserts have a large annual range of temperatures.

3. Equatorial region receives maximum insolation and heat throughout the year. The hot air rises up creating low pressure in this area.

Below diagram illustrates the structure of the atmosphere:

1. Chinook — It blows down the slope of Rockies in parts of U.S.A.
2. Mistral — It blows on the shores of North-west Mediterranean Sea, in Rhone Valley.
3. Foehn — It blows in the valley of the northern Alps.
4. Loo — It blows in northern plains of India during summers.

(i) A zone of low pressure lying parallel to equator where North-East and South-East trade winds converge and meet each other, producing calm and light surface winds and a strong upward movement of air is called Doldrums.

(ii) It is called so because the word Doldrums is associated with a gloomy, listless mood, perhaps reflecting the sultry air and variable breeze found there.

Below diagram shows formation of sea breeze:

1. Roaring forties and furious fifties are found in the Southern hemisphere because there is no obstruction in the path of the wind.
2. In the sub-tropical region the descending air gets divided into two parts. One part blows towards the Equatorial Low Pressure Belt. The other part blows towards the Circum-Polar Low Pressure Belt. This zone is marked by ascent of warm Sub-Tropical air over cold polar air blowing from poles. Due to earth's rotation, the winds surrounding the Polar region blow towards the Equator. Centrifugal forces operating in this region create the low pressure belt, known as Circum-polar low pressure belt.
3. Cyclones originate due to low pressure. It brings rain and with conclusion there is increase in humidity. It results in high pressure which leads to anticyclone. It happens mostly in case of Temperate cyclone.

(i) Convectional rainfall

(ii) Two characteristic features of the convectional rainfall are:

1. This type of rain mostly occurs at 4 o'clock in the afternoon.
2. It is always torrential accompanied by lightening and thunder.

(i) When cold air holding moisture, comes in contact with objects like flowers, leaves, glass particles etc., it condenses to form tiny drops called dew.

(ii) Dew is in liquid state and is found at places having low temperatures while frost is in solid state and found in places having temperature below 0°C. Dew is not harmful for crops while frost is very harmful for crops and plants.

(iii) Fog is formed when warm and moist air moves along the surface of colder region. Its temperature goes down to dew point. Thus, fog is commonly formed in the winter season.

1. The moisture laden winds strike the mountain and cannot cross the mountain. They cool down as they rise along the mountain and shed their moisture in the form of rain on the same side (windward side). By the time they reach the leeward side, they are devoid of moisture or have very low moisture content. Therefore, the other side (leeward side) remains dry and is known as rain-shadow area.

2. Frontal rain is common in mid latitudes because it is the zone of convergence of warm westerlies and cold polar easterlies.

3. Convectional rainfall is very common in equatorial region around 4 o'clock as the surface gets heated up during this time. Therefore, convectional rainfall is also called 4 o'clock rainfall.

Industries release different toxic gases into atmosphere. Burning of fossil fuels releases sulphur dioxide, carbon dioxide and carbon particles. Vehicles also release carbon particles, carbon monoxide and smoke into the atmosphere. They also release unburnt hydrocarbons. Therefore, industries and vehicles are the most important cause of air pollution.

Radioactive waste is generated from nuclear power stations, nuclear weapon testing, mining etc. They are also generated from hospitals, radio-tracers etc. Handling this waste is risky as it can cause cancer, acute radiation syndrome, cardiovascular diseases etc. It can be very dangerous to skin and eyes as this waste is geno-toxic material.

(i) Organic farming is a farming method that involves growing and nurturing crops without the use of synthetic based fertilizers and pesticides. This process involves the use of biological materials, avoiding synthetic substances to maintain soil fertility and ecological balance thereby minimizing pollution and wastage.

(ii) Organic farming is gaining popularity in recent times as there is increasing awareness among people regarding the harmful effects of chemicals used in farming. Risk of entry of toxic chemicals in food chain and biomagnification, is inspiring people to promote organic farming.

Individuals may reduce energy consumption to create a cleaner and eco-friendly world by adopting the following measures:

1. carpooling
2. promotion of public transport
3. restricted use of fossil fuels
4. saving energy like electricity and fossil fuels

This will contribute to a cleaner environment. Increasing dependence on renewable forms of energy will help a great deal in creation of a cleaner and eco-friendly world.

The major hot deserts of the world are found on the Western margins of the continents because the trade winds blowing from North-East to South-West shed their moisture on the Eastern side and become dry by the time they reach the western side.

Cattle rearing is one of the most important economic activity practised in the tropical grasslands. They rear cattle for meat skin and hide. The cattle rearing is still in subsistence level in Llanos but is done on commercial basis in most tropical grassland like Campos and Savannas.

1. The Equatorial region is also called the lungs of the world because it has large tropical rain forests which act as a sink for carbon dioxide and provide us oxygen.

2. The trees found in the Mediterranean region have long roots and thick barks because they show xerophytic adaptation. In order to increase their efficiency of water absorption they have long roots. They have thick barks to reduce transpiration losses.

3. Tundra region has a low annual range of temperature because this region is cold throughout the year. Summers are mild.

(i) The Cool Temperate Continental type or Siberian type of climate is found in the north-western part of Europe.

(ii) This region is sparsely populated. Farming is not an important economic activity as land is covered with snow during long winters. Some crops like barley, oats, rye, potatoes and beetroots are grown in the sheltered valleys bordering Steppes.