 Hello everyone, so today we are going to discuss previous year geography questions, UPSC, previous year question from the year of 2011, so totally 2022. This is first session, in this session we will be discussing around 40 questions, okay, so we will see particularly how to eliminate options because geography is the thing which is very broad, so for normal other optional students geography technical concept may be little bit difficult, so we will particularly focus on elimination method, so which may be useful, okay, so can we start, so which one of the following set of elements was primarily responsible for the origin of life on earth, see it is actually very basic question, oxygen evolved later correct, so when new organisms evolved photosynthesis process evolved oxygen was added, so it is not in the previous time, so oxygen evolved later, so we can eliminate oxygen here, so if you eliminate oxygen option A and C can be eliminated easily, so just two options left carbon, hydrogen, nitrogen, carbon, hydrogen and potassium, so obviously it is nitrogen, carbon, hydrogen and nitrogen is the exact answer, so one option B, I think it is 2011 question, okay, so second, consider the following statements, earth magnetic field, earth magnetic field has reversed every few thousand years, when the earth was created more than four thousand million years ago there was 54 percentage of oxygen under no carbon dioxide, when living organisms originated they modified the early atmosphere, the earth magnetic field has reversed every few thousand years, these are the three keywords, okay, so now coming back to the options, the third statement is very easy, right, just now we have discussed when living organisms originated particularly due to photosynthesis and other factors the earlier composition of atmosphere was changed which became conducive for later evolution, so third statement is definitely true, so you can eliminate option 1 where there is no option 3, so just the three options, so now our probability increased to 25 from 25 to 33 percentage, we have eliminated one option, second, when the earth has created was created more than four thousand million years ago there was 54 percentage of oxygen and no carbon dioxide, so again this is extreme statement, I am not mentioning that if there is any extreme statement it is definitely wrong but if there is any extreme statement we have to rethink, we have to revisit that particular statement again, actually early atmosphere have more carbon dioxide, later oxygen evolve, so second statement is definitely wrong, so we can eliminate second statement, so we have left it just to one statement it is option CC for Chennai, okay, so we did not see even first option, whether earth magnetic field has reversed or it is normal throughout the time, see it is reversed but we did not see that particular option, we went for elimination and we have arrived into the correct option option C, the earth magnetic field has reversed, yes every 200,000 to 300,000 years earth magnetic field has reversed, so that is the fact, so first statement is true, third statement is true but second statement it is false, so second option C, okay, so third, which of the following phenomena might have influenced the evolution of organisms, see can you understand the question, so first three questions is mostly about evolution, origin of your from Big Bang theory you have to study, it is in our NCRT itself, okay 11th NCRT, so which of the following phenomena might have influenced the evolution of organisms, continental drift and glacial cycles, it is true, option C both one and two, select the correct answer, see most of the time you look for whether sometime if they select the, which option is not correct or sometime they ask which option is correct, so you once go through these statements, okay, so which of the following phenomena, continental drift and glacial cycles, both option is correct, for example initially we know, initially there is Panjia surrounded by water body, Panthalasa, Panjia broke into two low ratio Gondwana, Gondwana continents further divided into many continents, for example South Africa, sorry South America, Africa, India, Australia, Antarctica, so with the movement of plates, if the movement of continents evolution of organisms happen, for example Australia, it is isolated for a longer period of time, so the species in Australia is very unique, so evolution of species, continental drift is the important factor plus glacial cycle, see the last period is tertiary period, currently we are living in quaternary period, quaternary period can be divided into two epochs, one it is Holocene and second Pleistocene, Pleistocene is the last ice age, Holocene is the present warm age, so when earth move from Pleistocene to Holocene epoch, from ice age to warm age period, there is evolution of many organisms, at the same time there was extinction of organisms also, the earth has experienced five major mass extinctions before, so glacial cycle has a role definitely, so second option is also correct, so three option C, okay four, consider the following electromagnetic radiation, geothermal energy, gravitational force, plate movements, rotation of earth, revolution of earth, which of the following are responsible for bringing dynamic changes on the surface of earth, see in this electromagnetic radiation plays a major role, yes it plays a major role, it impacts radiation temperature changes, which have an impact on metamorphism or weathering process, so definitely, geothermal energy, magnetic eruption and lava flow created changes in earth land form, gravitational force, yes it impact mass movements, particularly due to gravity, it impacts mass movements, yes it is definitely true, for example, landslides, plate movements, yeah obviously there is, we know about conversion plate boundary, diversion plate boundary transform, so the movement of plates definitely have an impact on surface, for example, recent if it is current affairs, Turkey and Syria earthquake, because of Anatolian plate, it is in the tri-junction, Arabian plate and Eurasian plate, so plate movements have definitely have an impact, rotation of earth and revolution of earth is the key term, see you can eliminate option A and D, okay so you have left only two options, 1, 2, 3, 4 and 1, 2, 3, 4, 5, 6, now the tricky part is rotation of earth or revolution of earth make an impact on the surface of earth, so most probably you may choose option A or sometime you may choose option D, according to UPSC official answer key, it is option D, defer deli, okay so rotation of earth and revolution of earth, rotation of earth have an impact on wind movement, have an impact on ocean currents, have an impact on sunlight, at the same time revolution of earth will tilt in its axis, have an impact on seasonal effects, for example, there is a change in intensity of sunlight across space, northern hemisphere and southern hemisphere, there is a difference which may also have an impact, so wind movement, ocean currents or sunlight variation due to rotation and revolution of earth making changes at the earth surface, so four option D, defer deli, so far we have discussed very basics, the first evolution of organism, second it is about magnetic field and early atmosphere, third evolution of organism, fourth geomorphology concept, so fifth concept, this is map based question, we can expect one or two map based question each and every year, so which of the following pair is correctly matched, so it is very easy actually, if you know the answer, atlas mountain is the correct answer, so consider Africa, North-Western part of Africa we have atlas mountain, Morocco, Tunisia, these countries, so atlas mountain, North-Western Africa it is true, then what about Abyssinian plateau it is in Ethiopia, Guyana highlands it is in Venezuela, South America, Okwango basin also called as Kalahari basin, it is in Botswana under parts of Namibia, so five option B basic world map reading, so five option B before Bombay, six, consider the following statements, in India the Himalayas are spread over five states only, so only extreme statements, so Himalayas are spread over five states only, see actually if you understand the pattern Himalayas extend from west to east, from Jammu and Kashmir, Himachal Pradesh, Uttarkan, even parts of Punjab we have Sivaliks, plus UP, Bihar, Sikkim, Arunachal Pradesh, poor one cell, so they did not mention about western Himalayas, it also includes eastern Himalayas, so it is definitely more than five states, so first option is wrong, you definitely know first statement is correct, so first statement is wrong, you can eliminate option A under option D, so now your chance is 50 percentage, you have eliminate two options, now back to the question, western guards are spread over the five states only, see this is very significant because due to human impact, ecological destruction, western impacts is undergoing major changes, Kasturirangan report particularly on Himalayan ecosystem and western guards is also very relevant, particularly for current affairs, so now coming back to the point western guards are spread over five states only, it is not five state, it is six state, for example Gujarat, Maharashtra, Goa, Karnataka, Kerala and Tamil Nadu, six states, so it is not five states, so second statement is wrong, so you can eliminate option C, so only option left is option B, three only, so now coming back to this statement, Pulikat lake is spread over two states only, yes it is spread over two states, one it is Andhra and second it is southern state it is Tamil Nadu, so Pulikat lake, so that is Palakir Kadiwari in Tamil, so six option B for Bombay, so very simple, basic map reading, seven with reference to water on the planet, consider the following statements, the amount of water in rivers and lakes is more than the amount of water at ground, amount of ground water, the amount of water in polar and ice caps and glaciers is more than the amount of ground water, see we have to know a very basic fact, 97 percentage we have ocean, nearly two to three percentage we have freshwater source, in this two percentage of freshwater it is in ice caps, glaciers, 0.68 percentage it is as ground water, so less than 0.01 percentage we have surface drainage as rivers, lakes, etc, so now coming back to this statement, the amount of water in rivers and lakes is more than the amount of ground water, it is definitely false, so first statement is wrong, second statement the amount of water in polar and ice, polar ice caps and glaciers is more than the amount of ground water, yes it is true, so seven option B to only, simple statement but this particular fact is very important, you have to remember, so seven option B for Bombay, eight, yeah it is very important, Gandhikota canyon, see we often know Grand Canyon in USA, Gandhikota canyon it is often referred as Grand Canyon of India, so it is previous question, recent question, Gandhikota canyon of South India was created by which of the following rivers it is Pennar, Andhra Pradesh it is in Kadapa district, so Gandhikota canyon river Pennar, do not confuse with Tenpennai it is different, Pennar is different, so eight option C, nine, this is also very good question, Namachapurva, Namachapurva it is in Garwal Himalayas, Nanda Devi, Kumaun Himalayas, Nakhrak Sikkim Himalayas, so option one and two, two only, one and three only, see very basic, if you learn about biosphere reserves, particularly UNESCO biosphere reserves or simply biosphere reserves, you may know, Nakhrak biosphere reserve it is in Meghalaya, Meghalaya particularly which hills are Garo hills, so Nakhrak Himalayas is definitely not in Sikkim, it is in Meghalaya, Nakhrak it is biosphere reserve, that is why it is very important also, so Nakhrak it is not Sikkim Himalayas, so definitely third option is wrong, so you can eliminate option C and option D, so only we have left with two options, so 50 percentage probability, so next Nanda Devi in Kumaun Himalayas, Nanda Devi biosphere reserve again, Nanda Devi is the second highest peak after Kanjanjunga, Kanjanjunga is the highest peak in Indian control, actually it is K2 but it is in POK, so Kanjanjunga is the highest peak in India, it is in Sikkim, second highest peak it is Nanda Devi, so it is in Kumaun Himalayas, it is in Kumaun Himalayas, Uttarakhand Himalayas region, so Nanda Devi the second statement is correct, so next Namachapurva, Garwal Himalayas, see actually we know about Syntaxial Bind, so Himadri terminates at Syntaxial Bind, at the two edges we have two peaks, one it is Namachapurva and second it is sorry, one it is Nangapurva and second Namachapurva, so Nangapurva it is in the western side, Namachapurva it is in the eastern side, why Nangapurva is very important, Indus turns into Pakistan near Nangapurva, Indus Garj, Brahmaputra turns into India near Namachapurva, Brahmaputra Garj is in Namachapurva, Namachapurva it is north of Arunachalpates in Tibetan region, so Namachapurva is definitely not Garwal Himalayas, Garwal Himalayas it is in Uttarkhand, so Namachapurva the second statement is definitely sorry, first statement is definitely wrong, so only one option is correct that is Nanda Devi it is in Kumavon Himalayas, so option B for Bombay, okay, so you just correlate your knowledge with environment or history or economics or some other subjects you can eliminate options, so 10. With reference to India consider the following statement it is very important considering our demand, monocyte is the source of rare earth, monocyte contains thorium, actually monocyte contains source of rare earth minerals and also it contains thorium, so both option is correct, so 1 and 2 is correct so you can eliminate option C, now back to question, so monocyte occurs naturally, yes it occurs naturally, in the entire Indian coastal sands in India it is definitely not true, it is extreme statement, it is not true actually I will give you statement but this is not true, so third option is wrong, so if you eliminate third option you will be left with just one option it is option 1, 2 and 4, we did not see fourth option itself, in India government bodies only can process or export monocyte as it is true, actually IREL, India rare earth limited under department of atomic energy is the only government body which have authority to process or export monocyte, so fourth statement it is correct it is IREL, India rare earth limited under department of atomic energy, third monocyte occurs naturally in entire Indian coast according to DAE department of atomic energy only few states have monocyte deposits, it is Odisha, Andrapati's, West Bengal and particularly Kerala, Tamil Nadu, so these are the five states which have good amount of monocyte deposits and parts of jargon but in very few percent, very 0.0 to something, so parts of jargon have monocyte deposits, only these states have good quantity of monocyte deposits, Odisha AP, West Bengal, Kerala and Tamil Nadu, so it is not entire coastal region, so third statement is wrong, so this is very important actually monocyte thorium nuclear reactors and all other facts, so 10 option B, B for Bombay, so 11, in the northern hemisphere the longest day of the year normally occurs in, see this is very very basic question based on revolution, based on the apparent movement of sun, the northward movement of sun or southward movement of sun, Uttarayan movement, Dakshinayan movement, correct, so actually consider sun the earth is revolving around sun in elliptical orbit, at some point March 21 under September the sun rays it is in equator, we call it as equinox, spring equinox atomic equinox but around June 21 the vertical sun rays it is in northern hemisphere, the vertical sun rays reach extreme tropic of cancer, December 22 it is around tropic of Capricorn, so June 21 summer solstice the northern hemisphere have longest day and shortest night, correct, so June 21 has the longest day in northern hemisphere, so June 21 second half of the month of June, so 11 option B, very basic question but they have twisted, so in the northern hemisphere the longest day of year it is second half of the month of June, June 21 where the day will be longest, night will be the shortest, it is during March to June it is the northward movement of sun Uttarayan movement particularly from equator to tropic of cancer, so 11 option B, 12 a layer of earth, a layer in the earth's atmosphere called ionosphere facilitates radio communication, so they have given ionosphere facilitates radio communication it is in our NCAT very basic question, we know about layers of atmosphere consider this is surface, troposphere, stratosphere, mesosphere, ionosphere and exosphere, so 5 layers, troposphere, stratosphere, mesosphere, ionosphere, thermosphere and exosphere, 5 layers we know that. The presence of ozone causes the reflection of radio waves into earth, very basic question, so ozone it is in the stratosphere, so it is not in the ionosphere, so second first statement is definitely wrong, so first statement is wrong, so answer cannot be 1 only or both 1 and 2, radio waves have a very long wavelength, yes radio waves have a very long wavelength it is true, but considering the question it is not supportive, radio waves are very long wavelength, but how ionosphere facilitates radio communication, so it is nowhere related to that, so even though it is the second statement, second statement is correct for the question it is not true, so 12 option D, D for Delhi, so ionosphere facilitates radio communication particularly the electrically charged particles called ions reflects radio waves, that is the exact answer we know that actually, so 12 option D neither one nor two, even though second statement is correct it is not exactly relevant for the question, so 12 option D, 13. The jet aircrafts fly very easily and smoothly in the lower at stratosphere what could be the appropriate explanation, there are no clouds or water vapor in the lower stratosphere and there are no vertical winds in the lower stratosphere, both option is correct, so it is option C to avoid a turbulence generally jet aircrafts flow in the lower stratosphere, so both options are correct, so 13 option C particularly to avoid turbulence, so 13 option C, you can understand C, 13th question, 12th question it is from the same topic, so if you understand just keep your focus on NCRTs, after completing NCRT you can go for reference book like GC Liang, NCRT particularly 11th and 12th NCRT is most important, 11th NCRT is particularly most important, so variations in the length of day time and night time from season to season, see they are asking variation in length of day, just now we have discussed, June 21, Northern Hemisphere experience longest day, shortest night, December Northern Hemisphere experience shortest day and longest night, so we know that this change, June 21, December 22, summer solstice, winter solstice, equinox, spring equinox, autumn equinox, we know that fact, June 21, Northern Hemisphere longest day, shortest night, December 22, Northern Hemisphere shortest day, longest night, because suns vertical sun rays will be in Southern Hemisphere around December, so equinox exactly 12 ha of day 12 ha of night, so variation in length of day time and night time from season to season or due to earth rotation causes day and night, but not a factor, earth revolution around the sun, yes in an elliptical manner, but revolution is not the exact answer, revolution of earth on a tilted axis that is the important factor, so option D, 14 option DD for Delhi, same concept apparent moment of northward shifting of sun and southward moment of 14 option D, 15 again the same kind of question and 21st June the sun, 21st June as we have discussed the suns vertical sun rays will be in Northern Hemisphere, it will be in tropic of cancer summer solstice, the sun does not set below the horizon at the arctic or at the Antarctic, vertically overhead at the noon of equator, no it is around March to September, sun vertically over at the tropic of Capricorn it is around December, sun does not below set below the horizon at the arctic circle is the correct answer, arctic circle experience 6 months of continuous day, at the same time during June month during northward moment of sun Antarctic circle experience continuous 6 months of night, so in this category in this question it does not set below the horizon at the arctic circle, so 15 option it is same concept 3 question it is repeated 16, the increasing amount of carbon dioxide in the air is slowly rising the temperature of the atmosphere because of it absorbs, say actually carbon dioxide greenhouse gas you know that, so it is slowly rising the temperature of the atmosphere because it absorbs infrared radiation, 16 option the infrared part of solar radiation, see earth generally it takes short wave radiation when there is energy from sun, when it is reflected back it is a long wave radiation, it is reflected from the surface or from the atmosphere, so generally these long wave radiation infrared radiation it is observed by carbon dioxide which increases the average global temperature that is the major concern, actually it is the protective layer greenhouse gases but due to anthropogenic emissions we are thickening the carbon dioxide or the increasing the extent of greenhouse gases which act as the we know about that particular topic right greenhouse effect, so that is the major problem, so answer the infrared part of solar radiation, so 16 option the long wave radiation, 17 normally the temperature decreases with the increasing height from the earth surface, yes we know that actually normal lapse rate for every 1 kilometer there will be an average reduction of minus 6.5 degree Celsius we call it as normal lapse rate we know that, what is the reason, so the atmosphere then first of all what is the reason for this temperature reduction when you go to higher altitude now, at the ground surface we have high density of air molecules, at the top surface we have scattered air molecules due to many reasons particularly gravity and all other factors pull ground air molecules towards the ground, so generally air molecules have will be have high density at the ground surface compared to the higher altitude, so now back to the question the atmosphere can be heated upwards only from the earth surface, yes it is true 17 next statement there is more moisture in the upper atmosphere actually there is more moisture in the lower atmosphere compared to the upper atmosphere, so second statement is wrong, so 2 options can be eliminated, so the air is less dense in the upper atmosphere yes we have discussed here at the ground surface we have high density of air molecule at the higher altitudes we have scattered air molecules less density, so the air is less dense in the upper atmosphere it is true, so third option is definitely true, so option it is C, so option C C for Chennai the temperature can be heated upwards only from the earth surface we have discussed it before, second there is more moisture in the upper atmosphere it is definitely wrong and third statement is correct, so 17 options C C for Chennai, 18 the annual see they are asking annual range of temperature please pay attention, the annual range of temperature in the interior of continents is high annual range in extreme heat in temperature extreme high temperature or extreme low temperatures, so range of temperature in the interior of continent is high as compared to coastal regions what is the reason, so if you consider India we can take Delhi or any coastal city Kulkata Chennai or Mumbai, so compared to the coastal cities interior part of the continents have extreme range of temperature the reason is because of continentality effect continentality effect less influence of water and second factor conduction process due to conduction process land acquires heat faster at the same time it cools rapidly but water due to conduction process it will heat and cool very slowly, so the thermal difference between land and water is the first only important factor, second variation in altitude between continents and the ocean see altitude can make a difference but it is a highly localized factor but whether it can create huge difference between continent and the oceans it is not definitely true presence of strong winds in the interior that is also not true third heavy rains in the interior as compared to the coast actually it is reverse due to marine influence coastal region will experience more rainfall compared to the interior parts, so fourth option is definitely wrong, so the option only option is option A, so the annual range of temperature in the interior of continent is high because of thermal difference between land and water we generally know about continentality character, so particularly Delhi can be best example, so 19 westerlies in southern hemisphere is stronger and persistent than in northern hemisphere, first of all we need to know westerlies are permanent wind system, so we know 4 pressure belts, equatorial low pressure belt, sub tropical high pressure belt, sub polar low pressure belt and polar high pressure belt, so westerlies it is between sub tropical high pressure belt and the sub polar low pressure belt, it is both in northern hemisphere and the southern hemisphere, so southern hemisphere has less land mass as compared to the northern hemisphere, yes it is true actually see the wind not only westerlies wind is affected by frictional force, the frictional force is very less in water body compared to the land, so which can reduce the velocity of wind, so southern hemisphere has less land mass as compared to the northern hemisphere is definitely true because of less frictional force westerly speed is very high, so that is why we refer westerly in southern hemisphere as a roaring 40 furious 50s because of it is wind speed in 40 degree latitude, 50 degree latitude the velocity of westerlies is really high, so first statement is correct second statement Coriolis force is high in southern hemisphere as compared to the northern hemisphere, see we know Coriolis force will have an impact on each and every moving object whether it can be a solid liquid or gases substances, there is no major difference between an northern hemisphere and southern hemisphere Coriolis force, first of all Coriolis force you know that it forms due to the rotation of earth, so but in this Coriolis force will have no impact, so 19 option A, so very important statement 20, consider the following statements again westerly, so consider the following statements the wind which blow between 30 degree north and 60 degree south latitudes through the earth are known as westerlies, actually when you are reading these kind of question with the pressure exam pressure most of the time you will fail to notice some important letters, see actually it is if according to this question consider this is equator 30 degree north, 60 degree south, so this entire region have westerlies impact according to this question, we definitely know it is 30 degree north to 60 degree north, 30 degree south to 60 degree south, but they have given 30 degree north to 60 degree south, actually this region have an impact particularly equator and tropic region we have impact of trade events, easterlies, so first statement is wrong this one word if they have given it is n, so obviously it is correct, but they have given southern latitude, so it is wrong, the moist air mass that cause winter rains in north western India are part of westerlies, see actually from mediterranean region there is one important z stream called subtropical westerly z stream, so actually it carries extra tropical cyclone from mediterranean sea towards indian subcontinent, when these extra tropical cyclone enters indian subcontinent it gives rainfall particularly to the north western part of India, we call that particular factors western disturbances, so in India two region experience winter rainfall, one it is north western part of India particularly due to western disturbances and second it is southern part of India, Tamil Nadu and coastal Andhra Pradesh due to the influence of north eastern ones and cyclones, so this second statement it is correct, so twenty option B for Bombay, first statement is wrong, second statement is correct, twenty one consider the following statements z stream occur in the north hemisphere, see extreme statement you can eliminate this option, z streams are both present in north hemisphere and southern hemisphere, so first option can be eliminated, second only some cyclones develop an eye, say actually if a cyclone have greater than 119 kilometer per hour, so generally that cyclones forms eye, eye region, center low pressure region, but if the velocity wind velocity is very less eye region is not well developed, so second statement it is correct actually, so third statement temperature inside the eye of a cyclone is nearly 10 degree Celsius lesser than the surrounding, we know that actually consider this is tropical cyclone eye region, so eye region have high temperature and the low pressure, so eye region is a low pressure system, so it has comparatively higher temperature than the surrounding region, so third option is definitely wrong, so option it is see very simple, from the surrounding region temperature increases towards the eye, if you take pressure from the surrounding region pressure decreases towards the eye, temperature increases towards the eye, pressure decreases towards the eye, so we need to know this basic fact it is very important, so z stream occur in northern hemisphere it is false, it also in southern hemisphere, only some cyclones develop an eye, yes it is exactly true once again, yes it is exactly true, if the wind speed is greater than 119 kilometer per hour we have proper development of eye, the temperature inside the eye of a cyclone is nearly 10 degree Celsius lesser, no it has higher temperature, so third statement is also wrong, so 21 option C 22, in the south Atlantic and southeastern Pacific region in tropical latitude cyclone does not originate what is the reason, see this is very important question, so most of the most of us choose this option, C surface temperatures are low because of cold ocean currents, yes it is true but the exact answer even according to UPSC's official key it is option B, intratropical conversion zone, ITC is it seldom occurs in this region because of low sea surface temperature, ITC is it mostly it will mean equator or north of equator, so it seldom occurs in the south of equator, so they have asked the south Atlantic and southeastern Pacific region, so ITC is it generally it is not present in south of equator due to low sea surface temperature, so this is an important factor why cyclones does not originate in south Atlantic and southeastern Pacific region, so 22 option B. Coriolis force and absence of land it is not a factor, coriolis force is exactly the same as northern hemisphere, absence of land is not a major impact, so 23 on the planet earth most of the freshwater exist as ice caps, we have discussed the same question before, out of the remaining freshwater the largest to proportion after ice caps and glaciers out of the remaining freshwater the largest to proportion exist as ground water, so 23 option C already I have given data, so 23 it is option C, 24 why are dew drops not formed on a cloudy night, so consider this is a surface when there is cloudy night dew drops are generally not formed what is the reason, clouds observe the radiation released from the earth surface, cloud reflect back earth radiation, the earth surface would have low temperature on cloudy nights, clouds deflect the blowing wind, so answer it is option B, earth reflect back the radiation which is emitted from the earth surface that is the exact answer, clouds reflect back the earth radiation that is answer, particularly for dew drops we need clear sky, this is important clear sky, less wind and high relative humidity, these are some of the factors which creates dew drops, so first important factor we should have a clear sky, but if we have a cloudy night, so obviously it hinders dew drops formation, so 24 option B 25, during a thunderstorm a thunder in the sky is produced by meeting of cumulonimbus, lightning that separates nimbus, violent upward movement of air and water particles, actually the thunder due to lightning the air in the surrounding region expand and this creates sound waves, so that is the source for thunderstorm, so in this option no statement is correct, so none of the option it is option D, it is initially believed meeting of cumulonimbus clouds in the sky, it is the reason for thunder, but it is not the exact fact, due to lightning due to the increase in temperature and pressure the air molecules get expanded which creates sound waves called thunder, so that is the exact answer, so expansion of air molecules, expansion of surrounding air molecule that is the exact answer, so 25 option D, 26 again El Nino La Nina concepts, recent question, La Nina is suspected to have caused the recent floods in Australia, how is La Nina different from the El Nino, so we need to know the difference between El Nino and La Nina before, so La Nina is characterized by unusually cold ocean temperature in equatorial Indian ocean, see actually we know that El Nino and so El Nino and La Nina it is due to the sea surface temperature variation in Pacific ocean not in Indian ocean, so the first statement it is wrong, so 26, first statement it is wrong whereas El Nino is characterized by unusually warm ocean temperature in the equatorial Pacific, but La Nina it is not in Indian ocean it is Pacific, El Nino has adverse effect on the southwest monsoon, but La Nina has no effect on monsoon it is also false, La Nina have positive impact on monsoon, we experience more than average rainfall during La Nina period southwest monsoon particularly, El Nino period there is a less than average rainfall during southwest monsoon, so El Nino has an adverse impact, but also La Nina have positive impact on monsoon rainfall, so second statement it is also wrong, so option D, so 26 option D both the statement is wrong it is Indian it is given as Indian ocean that is false and it has adverse effect, but La Nina also have an impact, so it is again extreme statement, so 26 option D, 27 with reference to IOD, we can expect these kind of questions again El Nino IOD, so these factors we can expect repeatedly because it is in current of years it has a long-term impact, so obviously we have to focus with reference to IOD sometime mentioned in news while forecasting Indian monsoon which are the following statements are correct, IOD phenomena Indian ocean dipole is characterized by a difference in sea surface temperature yes it is true, between tropical western Indian ocean and tropical eastern Pacific, so you can see the same pattern like before, so actually IOD is a phenomena difference in sea surface temperature between Indian ocean for example, consider this is Arabian sea as a western pole, eastern Indian ocean as the eastern pole, so it is the difference in sea surface temperature between western pole and eastern pole, we consider it as IOD, positive IODina western pole will have warmer waters, eastern pole will have cold waters, negative IODina western pole will have cold waters, eastern pole will have warm waters, so it is confined to Indian ocean it is not related to Pacific, so one first option is definitely wrong second option, an IOD phenomena can influence an El Nino impact on the monsoon, actually even though monsoon for example, we consider El Nino, El Nino have a negative impact on monsoon we have discussed it before, if we have positive IOD as I have mentioned positive IODina western pole will have warmer waters, if we have positive IOD even it can negate the effect of El Nino, so even if there is an El Nino during positive IOD we will get above average rainfall or good rainfall during southwest monsoon season, so second statement IOD phenomena can influence yes it can definitely influence, so option it is B B for Bombay, so 27 option B, 28 what could be the main reason for the formation of Africa and Eurasian desert belt, see generally three important conditions for desert formation, one it is sub-tropical high pressure belt and second it is offshore winds third it is cold ocean currents, three most important reason they have given it is located in this sub-tropical high pressure cell it is correct it is under the influence of warm ocean currents actually as I have mentioned third condition it is under the influence of cold ocean current we have deserts actually warm ocean current generally creates rainfall due to high evaporation, so 28 second statement is strong first statement is correct, so 28 option A, if we need an example for example Africa Sahar and desert Sahar and desert forms due to canary current, so consider this is Africa Sahar and desert forms due to canary current which is the cold ocean current, so cold ocean current have an impact for example if you take Namib desert it is Benghula current, so cold ocean current again, so cold ocean current is the important factor, so 28 option A 1 only, 29 which of the following is the characteristic feature of tropical savanna region, savanna region you also learn about Sudan type of climate it is in your GC Liang Sudan type of climate is very important, so which one of the following is the characteristic climate of tropical savanna region rainfall throughout the year actually it is equatorial region we experience rainfall throughout the year rainfall in winter only generally in mid in Mediterranean climate we will have rainfall during winter okay, so extreme short dry season no it is not true, so it has definite dry and definite wet season that is the exact fact, so 29 option D is the correct answer, so rainfall throughout the year it is equatorial climate wet, equatorial climate rainfall in winter particularly Mediterranean climate due to the influence of westerlies, so definite dry and wet season is correct 30, climate is extreme rainfall is canty and the people used to be nomadic herders, the other statement best describes, so actually you can eliminate tundra and prairie easily but you may stuck with two options, African savanna and Central Asian steppe, both have extreme say actually African savanna also have nomadic people Central Asian steppe also have nomadic people but climate rainfall is not scanty in African savanna, African savanna receive around moderate rainfall, so it is not scanty and climate yes it has diurnal variation but here according to this statement in this above statement Central Asian steppe it is the exact answer, so 30 option B for example Kyrgyzstan there are many nomadic herders Kyrgyz, so that is the exact answer, so 30 option B, so particularly focus on tropical grassland savanna, temperate grassland steppe prairie we can expect similar kind of question, so 30 option B, 31 the seasonal reversal of wind is the typical characteristic of reversal of winds you know that is very easy question it is monsoon climate 31 option C for example if you take Indian south west south Asia monsoon actually during south west monsoon we have wind movement from sea to land but during north eastern monsoon that is during southward movement of sun there is reversal in wind direction that is from land to sea, so south west monsoon sea to land north east monsoon land to sea, so monsoon climate we have reversal of wind direction, so 31 option C 32 each day is more or less the same that is no major variation, the morning is clear and bright with the sea breeze and suns climb high in the high sky vertical sun rays heat mounts up dark clouds form then rain comes with the thunder and lightning but rain is swung over this explain actually this explains equatorial climate wet hot wet equatorial climate which experience convexional rainfall, so actually in equator region it experience vertical insulation high insulation of sun rays the air gets expanded it rises above it condense and it forms clouds which results in daily rainfall, so 32 option B is the correct statement 33 say these question tropical savanna desert formation 28 tropical savanna nomadic herders that is central asian steppe the seasonal reversal of winds then fifth statement hot wet equatorial climate all these question you can answer by reading second part of your gc liang gocheng liang second part they have discussed the various climate pattern if you read that basic vegetation and climate we can answer most of these questions, so okay so five questions we can expect similar question in upcoming years also so 33 consider the following statement high clouds primarily reflect solar radiation and cool the surface low clouds have high absorption of infrared radiation high clouds low clouds low clouds have high absorption of infrared radiation emanating from the earth surface and thus cause warming effect actually it is reverse actually high clouds on the it reflect actually low clouds because it is very thick it can reflect back the solar radiation it has high albedo effect actually that is why equatorial region even though it experience high insulation it has less salinity compared to the northern part of equator because equator region have thick cloud cover which have high albedo effect that can reduce the insulation to certain extent so thick clouds low clouds is very thick which can reflect solar radiation and cool the earth surface but high clouds have high absorption capacity it is very thin absorption of infrared radiation emanating from the surface and thus cause warming effect so it is the reverse so 33 option d neither one nor two okay so high clouds are thin second option low clouds are thick high albedo effect high albedo effect which can cool the earth surface so 33 option d neither one nor two 34 this question is not proper we will discuss it later 35 with reference to ocean mean temperature which of the following statement are correct omt is measured up to the depth of 26 degree celsius isotherm isotherm we know imaginary line joining the same temperature points which is 129 meters in the southwestern indian ocean omt collector during january march can be used using assessing whether the amount of rainfall in monsoon will be less or more than a certain long term mean average okay see actually it is current of years based question at that year there is a one current of years in newspaper actually IATM Pune Indian Institute of Tropical Metrology Pune actually evolved found this particular studies ocean mean temperature based prediction actually initially we generally predict monsoon by snow cover in tibet or some other facts particularly sea surface temperature by studying sea surface temperature we predict monsoon whether we will have average monsoon or above average or less than average monsoon generally we will study about sea surface temperature but what is the problem with sea surface temperature it can be influenced by many factors for example a wind inflowing wind can alter sea surface temperature or ocean currents can alter sea surface temperature or anthropogenic reasons can impact sea surface temperature so its success rate is comparative less in predicting monsoon so they have developed a new study called ocean mean temperature study from the surface for example from the surface at a certain depth in 26 degree Celsius in isotherm 26 degree they study mean temperature and they predict Indian monsoon whether we will have average monsoon or less than average or greater than average but the fact is that they have given 129 meter but actually it is around 59 meter it is not 129 meter but it is very difficult kind of question if you don't know the question we may know about OMT but these kind of numbers we may most often we end up in wrong side so if you don't know exactly don't attend these kind of question because it will backfire because if you don't know exactly the data don't take a raw guess for these kind of question better skip this question because we have negative marks obviously so first statement is wrong second statement it is correct so option B so 35 option B 36 consider the following factors which are the above factors influence ocean currents very basic question actually this here means also they have asked the question what are the factors which influence ocean currents so we can expect this question again so consider the following factors rotation of earth air pressure and wind density of ocean water have an impact for example rotation of earth creates equatorial currents from west to east air pressure and wind definitely have an impact hot wind and cold wind mix up ocean water which may have an impact density of ocean water it is also have an impact particularly between ecotartopolar region so revolution of earth actually have no role in the ocean current formation so fourth option is wrong so option it is 1 2 and 3 but very good question we can expect this question again in mains also 37 what explains the eastward flow of equatorial counter current see actually earth rotates from west to east so actually the water get piled up in the eastern side so equatorial currents generally move from west east to west direction I will repeat the point so due to rotation of earth from west to east water get piled up in one region so equatorial current north equatorial current south equatorial current move from east to west so again water pile up in some region so this convergence of equatorial current creates a new current called equatorial counter current so the exact answer it is the convergence of two equatorial current first we have to know equatorial current forms due to the rotation of earth from west to east so due to the convergence of equatorial current equatorial counter current is formed so that is the exact answer this is very good question very important question so regarding ocean currents if there is a question instead of equatorial counter current if they ask equatorial current it is rotation of earth that creates equatorial current formation but the question is equatorial counter current so 37 38 tides occurs in the ocean and see due to which of the following gravitational force of sun gravitational force of moon centrifugal force of earth see consider this is earth gravitational force of sun moon will have an impact which can create height at the same time Newton's third law for every action there is equivalent opposite reaction so there is centrifugal force which acts in the opposite side so three reasons is correct so 38 option d d for daily 38 option d 39 actually this question is repeated we have discussed ocean mean temperature and we have discussed factors influence ocean currents and we have discussed equatorial counter current also and now we have discussed tides so these four questions are repeated so just we are skipping in tropical zone the western sections of oceans are warmer than the eastern section owing to the influence of trade winds say consider in tropical temperate region tropical region temperate region tropical region we have the influence of trade winds so trade winds are easterlies from east to west direction westerlies are west to east direction so trade winds are region in tropical region eastern there due to the influence of trade winds western section of oceans are warmer yes it is true due to the influence of trade winds it carry warm waters towards the coast so consider in oceanic perspective western section of oceans is warmer due to the influence of trade winds from this trade winds from east to west easterlies in the temperate zone westerly make the eastern section of oceans warmer than the western section as it is true consider this is the path of westerlies it is moving from west to east so it carry warm waters towards the eastern coast of the ocean so both statement is correct so option it is important question very technical question so 43 option C I will repeat the point tropical region trade wind impact trade wind move from east to west so it carries warm water towards the western coast of ocean it is in oceanic perspective not in land perspective westerly move from west to east it carries warm waters towards the eastern coast so eastern side of the oceans generally have warmer waters very important question so 43 option C and last question it is kind of current affairs environment and geography with reference to Indian laws about wildlife protection considering the following statements say actually we have important act wildlife protection act 1972 according to wildlife protection act wild animals are the sole property of government as it is true second when a wild animal is declared protected such animal is entitled for equal protection whether it is found in protected areas or outside it can be a national park it can be a wildlife sensory or it can be outside the protected zone wild animals should be equally protected it is also according to WPA but can you read the state third statement apprehension of a protected wild animal becoming a danger to human life is sufficient ground for its capture or killing so it will be ultimate chaos so everyone everywhere there will be a risk of attrition between wildlife wild animals and the human habitations and human cultivations like farm farm farmlands and everything so if this is the cause if they can kill these kind of animals there will be absolute chaos so according to this act see if wildlife warden should permit killing of a particular animal we have incident of tiger there are some incidents so see if wildlife warden need to approve so it is not this statement this is wrong definitely so third statement it is wrong so option it is a 1 and 2 see whatever may be the question so by simple applying of logic particularly for geography by applying of logic and by elimination method you can almost answer many of the question it may look tough some of the technical questions but if you apply basic logic and basic ncrt data we can eliminate most of the options plus you have to update with current affairs particularly map based reading so we have three months left two and a half months left so we have adequate time particularly focused on map based questions okay with this we will wind up today's session thank you so much and have a good day thank you