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Understanding Society: India and BeyondCh 3 Atmosphere aur Climate

Atmosphere and Climate: Class 9 Social Science Chapter 3 Hinglish mein

Understanding Society: India and Beyond Part 1 · Hinglish notes, simulations aur practice · Official NCERT chapter PDF ↗

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  • 72 min
  • 1 simulation
  • 20 practice questions
  • 23 MCQs

Is chapter mein aap kya seekhenge

  • Atmosphere ko banane wali gases ke baare mein batao aur samjhao ki trace gases aur water vapour kyun zaroori hain
  • Atmosphere ki paanch layers ke naam kram se batao aur har layer mein temperature aur halaat kaise badalte hain, yeh samjhao
  • Weather aur climate mein farq karo aur samjhao ki temperature, humidity, precipitation, pressure aur wind aapas mein kaise jude hain
  • Land aur water ke asmaan garam hone se land breeze, sea breeze aur south-west aur north-east monsoon samjhao
  • India ke chaar seasons aur chhah paramparik ṛtus ke baare mein batao, aur climograph padho
  • Climate change ke kaaran aur asar samjhao aur carbon footprint kam karne ke tareeke sujhao
  • 2025 ki Punjab floods ko case study lekar flood disaster ke natural aur human kaaranon ka analysis karo

NCERT Social Science Class 9, Chapter 3, pp. 39–59 par based original companion text. Yeh NCERT se juda nahi hai aur NCERT ne ise endorse nahi kiya hai.

June ki shuruaat mein kisi subah Kochi ke beach par khade ho jao, to baarish aane se pehle hi uska ehsaas ho jaata hai. Samundar se ek nam hawa andar dhakelti hai, nariyal ke pedon ke upar grey baadal jamaa hone lagte hain, aur ek ghante ke andar galiyon mein paani behne lagta hai. Hawa, baadal, tez baarish aur geeli mitti ki khushboo bhi, yeh sab hamare planet ke chaaron taraf hawa ki ek patli chaadar ka hissa hain.

Yeh chaadar hai atmosphere (वायुमंडल). Har toofaani baarish, heatwave aur breeze mein atmosphere hi kaam kar raha hota hai, isliye yeh weather aur climate dono ko control karta hai. Yeh chupchaap tareeqon se bhi hume zinda rakhta hai. Ek kambal ki tarah yeh zameen ko har raat apni saari garmi khone se rokta hai. Yeh Sun ki zyaadatar nuksaandeh ultraviolet light ko rok deta hai, aur hume saans lene ke liye oxygen deta hai. Earth ki gravity ise apni jagah par pakde rakhti hai,Gravity woh khinchaav hai jo mass wali har cheez doosri cheezon par lagati hai. Earth ka khinchaav Moon ko uske orbit mein rakhta hai aur hawa ko space mein bhatak kar jaane se rokta hai. isliye hawa surface ke paas sabse ghani hoti hai aur upar jaate-jaate patli hoti jaati hai.

Definition
Atmosphere

Mili-juli gases ka kambal, jo Earth ki gravity se tika hua hai aur hamare planet ko chaaron taraf se dhake rehta hai.

ExampleClassroom mein jo hawa tum saans mein lete ho, woh atmosphere ka sabse nichla hissa hai.

Is chapter ke ant tak tum in chaar sawaalon ke jawab de paoge:

  1. Hawa kis cheez se bani hai, aur zameen se space tak atmosphere kaise arranged hai?
  2. Atmosphere ki har layer Earth par life ke liye kya karti hai?
  3. Monsoon winds India mein baarish kyun laati hain, aur har saal woh ulti disha mein kyun mud jaati hain?
  4. Hamara climate kis wajah se badal raha hai, aur hum mein se har koi greenhouse gases mein apna hissa kaise kam kar sakta hai?

3.1 Atmosphere ki Composition aur Structure

3.1.1 Atmosphere ki Composition

Hawa khaali dikhti hai, phir bhi yeh kai gases ka mixture hai. Maan lo tum dry air ke ek sample ko 100 barabar hisson mein baant sako. Unmein se lagbhag 78 hisse nitrogen honge aur lagbhag 21 hisse oxygen. Baaki har gas ko bache hue sirf ek hisse mein samaana padta hai (Fig. 3.1).

4/4Aakhri hissa zyaadatar argon hai, saath mein thodi si carbon dioxide aur doosri gases.

Fig. 3.1Do gases milkar dry air ka 99 per cent banati hain; baaki saari gases aakhri 1 per cent mein baant leti hain.NCERT Fig. 3.2 · p. 40

100 squares ka ek grid dry air ke ek sample ko dikhata hai, har square ek per cent hai. Pehle step mein saare squares khaali hain. Doosre step mein 78 squares bhare hain aur un par nitrogen, 78 per cent likha hai. Teesre step mein 21 aur squares, har ek par ek dot, oxygen, 21 per cent ke label ke saath hain. Aakhri step mein bacha hua ek square highlight hokar ek bar mein bada ho jaata hai: lagbhag poora argon hai, 0.93 per cent, saath mein carbon dioxide, 0.04 per cent, aur neon, helium aur ozone jaisi doosri gases, 0.03 per cent, ki patli pattiyaan.

Us aakhri 1 per cent ka zyaadatar hissa argon hai, ek aisi gas jo kisi se mushkil se react karti hai. Baaki mein thodi-thodi carbon dioxide, neon, helium, krypton, xenon, hydrogen aur ozone hai. Bahut chhoti maatra bhi bahut maayne rakh sakti hai, jaisa Table 3.1 dikhata hai. Green plants carbon dioxide se apna khaana banate hain, aur hamare bahut upar ozone ki ek patli layer Sun ki zyaadatar khatarnaak ultraviolet rays ko absorb kar leti hai.

Table 3.1Hawa ki kuch gases kya karti hain
GasDry air mein hissaYeh kyun zaroori hai
Nitrogenlagbhag 78 %Soil bacteria ise aise compounds mein badalte hain jo plants ko badhne ke liye chahiye.
Oxygenlagbhag 21 %Living things iska use khaane se energy nikaalne mein karte hain; fuels ko jalne ke liye iski zaroorat hoti hai.
Argonlagbhag 0.93 %Mushkil se react karti hai; kuch light bulbs bharne aur welding mein use hoti hai.
Carbon dioxidelagbhag 0.04 %Plants iska use khaana banane mein karte hain; yeh heat ko bhi trap karti hai.
Ozonebahut thodi si maatraUpar iski ek layer nuksaandeh ultraviolet rays ko absorb karti hai.

Do aur cheezein 'dry air' mein nahi gini jaatin kyunki unki maatra badalti rehti hai. Water vapour thande desert ke upar lagbhag na ke barabar ho sakti hai, lekin garam tropical sea ke upar hawa ka lagbhag 4 per cent ho sakti hai. Dust, dhuan, pollen aur sea spray ka namak bhi hawa mein tairte rehte hain. Yeh kan jitne dikhte hain usse zyaada maayne rakhte hain. Water vapour in par condense hokar cloud droplets banati hai, isliye inke bina baadal bahut kam bante aur baarish bhi kam hoti.

Quick check
3 mein se 1
Dry air ka sabse bada hissa kaun si gas banati hai?
Answer dekho

Answer (D) Nitrogen

Nitrogen dry air ka lagbhag 78 % hai. Oxygen par hum sabse zyaada dhyaan dete hain kyunki hum use saans mein lete hain, lekin woh sirf lagbhag 21 % hai.

3.1.2 Atmosphere ka Structure

Munnar ya Shimla jaise kisi hill station tak bus se jao to tumhe do badlaav dikhte hain. Hawa thandi lagti hai, aur khadi chadhaai par saans jaldi phoolne lagti hai. Dono suraag batate hain ki upar jaane par atmosphere badalta hai. Hawa neeche sabse ghani hoti hai, kyunki upar ki saari hawa ka wazan use dabata hai, aur altitude ke saath yeh tezi se patli hoti jaati hai. Mixture bhi badalta hai: lagbhag saari water vapour sabse neeche ke kuch kilometres mein rehti hai, jabki zyaadatar ozone bahut upar jamaa hoti hai.

Definition
Altitude

Mean sea level se oonchaai. Samundar ke average level ko zero maana jaata hai, aur altitude aam taur par metres mein di jaati hai.

ExampleSamundar se 900 m upar base ek town ki altitude 900 m hai.

Scientists atmosphere ko paanch layers mein baantte hain. Inki boundaries round numbers par nahi kheenchi jaatin: har boundary wahan rakhi jaati hai jahan height ke saath temperature girna band karke badhne lagta hai, ya iska ulta hota hai. Zameen se upar ki taraf har layer ke baare mein padhte hue Fig. 3.2 mein temperature ki line ko follow karo.

5/5Exosphere halki gases ke nikalne ke saath space mein ghul jaata hai.

Fig. 3.2Atmosphere ki layers is baat se tay hoti hain ki height ke saath temperature kaise badalta hai.NCERT Fig. 3.3 · p. 41

Ek graph jismein upar ki taraf 0 se 120 tak kilometres mein height hai aur aadi disha mein minus 80 se 40 tak degrees Celsius mein temperature hai, layers ke liye rangeen bands hain aur sabse upar exosphere ke liye ek alag band hai. Step 1 mein 0 se 12 km tak troposphere ek baadal ke saath dikhta hai, aur temperature ki line zameen par lagbhag 15 degrees se girkar lagbhag minus 56 tak aati hai. Step 2 mein 50 km tak stratosphere, ek dotted ozone layer aur ek jet aircraft judte hain; line pehle seedhi rehti hai aur phir zero se thoda neeche tak badhti hai. Step 3 mein meteor ki lakeeron ke saath 80 km tak mesosphere judta hai; line girkar lagbhag minus 90 tak aati hai. Step 4 mein aurora ke pardon ke saath 80 km ke upar thermosphere judta hai; line tezi se upar mudti hai aur uske saath ek arrow par likha hai ki upar zyaada garam. Step 5 mein sabse upar exosphere judta hai, jahan patli gases space mein nikal jaati hain.

Troposphere (क्षोभमंडल) woh layer hai jismein hum rehte hain. Ismein hawa ka zyaadatar mass aur lagbhag saari water vapour hoti hai, isliye baadal, baarish, kohra, ole, thunderstorms aur dust storms sab yahin hote hain. Average mein yeh lagbhag 12 km moti hai. Garam equator ke upar yeh lagbhag 18 km tak phool jaati hai aur thande poles ke upar sikud kar lagbhag 8 km reh jaati hai. Yahan upar chadhne par hawa thandi hoti jaati hai, har kilometre par lagbhag 6.5 °C, isiliye oonchi chotiyon par May mein bhi barf padi reh sakti hai. Troposphere ek boundary par khatam hoti hai jise tropopause kehte hain.

Definition
Troposphere

Atmosphere ki sabse nichli layer, average mein lagbhag 12 km moti, jahan hum rehte hain, jahan lagbhag saara weather hota hai aur jahan height ke saath hawa thandi hoti jaati hai.

Tropopause ke upar stratosphere (समतापमंडल) hai, jo lagbhag 50 km tak jaata hai. Iski sabse mashhoor khaasiyat ozone layer hai, jiska zyaadatar hissa lagbhag 15 se 35 km ki oonchaai par hai. Ozone Sun ki ultraviolet light ko sokh leti hai. Isse neeche ke living things bachte hain aur hawa bhi garam hoti hai, isliye upper stratosphere height ke saath garam hota jaata hai. Yahan lagbhag koi baadal ya toofaan nahi hote, isliye hawa smooth aur sthir rehti hai. Isliye lambi doori ke jet aircraft lagbhag 10–12 km tak chadhte hain, troposphere ke top ke paas ya lower stratosphere mein, zyaadatar kharaab weather ke upar. Stratosphere stratopause par khatam hota hai.

Saaf raat mein tumhe shaayad ek 'shooting star' dikhe. Yeh space se aaya chattan ya dhool ka ek kan hota hai, ek meteoroid, jo har second das-das kilometre ki speed se hawa mein ghusta hai. Friction use itna garam kar deta hai ki woh chamak kar jal jaata hai, aur zyaadatar aisa mesosphere mein hota hai, jo lagbhag 50 km se lagbhag 80 km tak ki layer hai. Yahan height ke saath temperature phir se girta hai. Top ke paas yeh lagbhag −90 °C tak gir jaata hai, jo poore atmosphere ka sabse thanda hissa hai. Mesosphere mesopause par khatam hota hai.

Thermosphere lagbhag 80 km se shuru hokar lagbhag 700 km tak jaata hai; iska top Sun ki activity ke saath upar-neeche hota rehta hai. Yahan ke gine-chune gas particles Sun ki X-rays aur short-wave ultraviolet rays ko absorb karte hain, isliye temperature tezi se badhkar kai sau degrees tak pahunch jaata hai. Phir bhi hawa itni patli hai ki garam mehsoos nahi hogi: tum tak heat pahunchane ke liye particles bahut kam hain. Is layer ke ek hisse, ionosphere, mein electrically charged particles hote hain. Yeh kuch radio waves ko waapas zameen ki taraf bounce kar dete hain, jisse radio signals horizon se bahut aage tak pahunch paate hain. International Space Station samet kai satellites thermosphere ke andar hi Earth ka chakkar lagaate hain, aur auroras ke chamakte parde bhi yahin dikhte hain.

Exosphere sabse bahari layer hai, jo lagbhag 700 km se shuru hoti hai. Hawa itni patli hai ki ek gas particle kisi doosre se mile bina bahut door tak ja sakta hai. Hydrogen aur helium jaisi halki, tez chalne wali gases yahan se space mein nikal sakti hain. Unke raaste mein kuch nahi aata, aur Earth ke centre se itni door uska khinchaav bhi kamzor hota hai. Exosphere ka koi saaf top nahi hai; yeh bas dheere-dheere outer space mein ghul jaata hai.

Har layer neeche ki life ke liye ek kaam karti hai. Troposphere poore planet par paani aur weather ko le jaata hai, aur stratosphere nuksaandeh ultraviolet light ko rok deta hai. Mesosphere space ke zyaadatar malbe ko jala deta hai, aur thermosphere sabse tez X-rays ko absorb karta hai aur radio signals ko door tak jaane mein madad karta hai.

Quick check
4 mein se 1
Atmosphere ki layers ko zameen se upar ki taraf kram mein lagao.
  1. Stratosphere
  2. Exosphere
  3. Mesosphere
  4. Troposphere
  5. Thermosphere
Answer dekho
Answer
  1. Troposphere
  2. Stratosphere
  3. Mesosphere
  4. Thermosphere
  5. Exosphere
Zameen se upar: troposphere, stratosphere, mesosphere, thermosphere aur aakhir mein exosphere, jo space mein ghul jaata hai.

3.2 Weather aur Climate

Tumhare phone ka weather app aaj dopahar ke liye 'Thunderstorm, 31 °C' bata raha hai. Ek atlas kehta hai ki Jaisalmer mein saal bhar mein bahut kam baarish hoti hai. Pehli baat weather ke baare mein hai; doosri climate ke baare mein. Dono jude hue hain, lekin bahut alag time scales par kaam karte hain.

Weather (मौसम) kisi jagah par thode samay ke liye atmosphere ki haalat hai: is ghante, aaj, is hafte. Yeh tezi se badal sakta hai. Bengaluru ki ek chamakti subah chaar baje tak thunderstorm mein badal sakti hai, aur shaam ke liye plan kiya match dhul jaata hai.

Climate (जलवायु) woh pattern hai jo kisi jagah ya region ke weather ka lambe samay, aam taur par 30 saal ya usse zyaada, ka average lene par dikhta hai. Ismein aam utaar-chadhaav bhi shaamil hain. Weather batata hai ki aaj chhaata le jaana hai ya nahi; climate batata hai ki wahan ke ghar ko bhaari baarish ka paani girane ke liye dhalwaan chhat chahiye ya nahi.

Compare

Weather ya climate?

Weather

  • Ghante, din ya ek hafta
  • Jaldi badal sakta hai
  • Example: 'Aaj Mumbai mein bhaari baarish'

Climate

  • 30 saal ya usse zyaada ka average
  • Dheere badalta hai
  • Example: 'Mumbai June se September tak geela rehta hai'

3.2.1 Weather aur Climate ke Elements

Weather scientists, jinhe meteorologists kehte hain, atmosphere ko kuch aisi cheezon se describe karte hain jinhe woh measure kar sakte hain, jinhe elements kehte hain. Hamari roz ki zindagi mein paanch sabse zyaada maayne rakhte hain: temperature, humidity, precipitation, atmospheric pressure aur wind. Padhte hue dhyaan do ki har ek baaki par kaise nirbhar karta hai.

Temperature

January ki dopahar Chennai mein garam lekin Delhi mein thandi kyun hoti hai? Ek jagah ke doosri se zyaada garam hone ka main kaaran insolation (सूर्यातप) hai. Equator ke paas dopahar ka Sun saal bhar aasmaan mein ooncha rehta hai, isliye uski rays zameen par lagbhag seedhi padti hain. Poles ki taraf rays tirchhi aati hain, aur tirchhi beam utni hi energy ko zameen ke bade hisse par faila deti hai (Fig. 3.3). Ek torch ko table par seedha neeche chamkao aur phir use jhukao: jhuka hua spot bada aur dhundhla hota hai. To kul milakar, equator se poles ki taraf insolation aur temperature dono kam hote jaate hain. Temperature din aur raat ke beech, aur garmi aur sardi ke beech bhi badalta hai.

Definition
Insolation

Incoming solar radiation ka chhota roop: Sun ki energy ka woh hissa jo Earth tak pahunchta hai.

4/4Isse teen heat zones bante hain: torrid, temperate aur frigid.

Fig. 3.3Sunlight ki ek hi beam equator ke paas chhote hisse ko garam karti hai lekin poles ke paas patli fail jaati hai.NCERT Fig. 3.6 · p. 44

Earth ka side view ek circle ki tarah, jiske beech se equator kheencha hai aur left se parallel sunlight aa rahi hai. Step 1 mein ek beam equator par seedhi padti hai aur zameen ke ek chhote hisse ko roshan karti hai, jis par hot likha hai. Step 2 mein usi width ki ek beam northern mid-latitudes par tirchhi padti hai; yeh bade hisse ko roshan karti hai, jis par mild likha hai. Step 3 mein North Pole ke paas teesri barabar beam surface ko chhoo kar sabse bade hisse par failti hai, jis par cold likha hai. Step 4 mein north aur south mein 23½ aur 66½ degrees par lines banti hain aur heat zones shade hote hain: tropics ke beech equator ke aas-paas torrid zone, har hemisphere mein ek temperate zone, aur har pole ke aas-paas ek frigid zone.

Geographers is pattern se globe ko teen heat zones mein baantte hain. Torrid zone Tropic of Cancer (23½° N) aur Tropic of Capricorn (23½° S) ke beech hai. Is belt mein kahin na kahin saal ke kisi din dopahar ka Sun bilkul sir ke upar hota hai, isliye yahan garmi rehti hai. Do temperate zones har tropic aur Arctic ya Antarctic Circle (66½° N ya S) ke beech hain, jahan garmiyan garam aur sardiyan thandi hoti hain. Poles ke aas-paas ke frigid zones ko sirf tirchhi roshni milti hai aur woh thande rehte hain. Tropic of Cancer India ke beech se guzarta hai, isliye desh ka southern aadha hissa torrid zone mein hai.

SimulationSun kahan bilkul seedha chamakta hai?

Sun ke chaaron taraf ghoomti Earth ka model, upar se ek schematic scale par dekha gaya. Earth ka jhuka hua axis aur dono tropics bane hain, aur raat wala hissa shaded hai. Play dabane par Earth din-ba-din apne orbit par aage badhti hai. Ek readout date, season aur woh latitude dikhata hai jahan dopahar ka Sun sir ke upar hai, taaki tum use dono tropics ke beech khiskte hue aur yeh dekh sako ki kaun sa hemisphere Sun ki taraf jhuka hai.

Fig. 3.4Earth ko uske jhuke hue axis ke saath Sun ke chaaron taraf ghumaane ke liye Play dabao.
Try karo
  • Play dabao aur 'Sun overhead at' reading dekho. Yeh zyaada se zyaada kitna north aur kitna south jaati hai?
  • June ke aakhir mein aur phir December ke aakhir mein pause karo. Har baar kaun sa hemisphere Sun ki taraf jhuka hai?

Humidity

Kolkata mein August ki ek dopahar fridge se thandi bottle nikaalo, to ek minute ke andar us par paani tapakne lagta hai. Jaipur mein January ki dopahar yahi karo, to woh lagbhag sookhi rehti hai. Yeh boondein hawa se hi aati hain: yeh humidity (आर्द्रता) dikhati hain, yaani hawa mein water vapour ki maatra. Jab samundar, nadiyon, jheelon, geeli mitti aur pattiyon se paani evaporate hota hai, to vapour hawa mein jaati hai. Garam hawa thandi hawa se kahin zyaada water vapour rakh sakti hai, isliye garam, geeli jagahein aksar bahut humid hoti hain. Humid hawa garmi ko sehna bhi mushkil bana deti hai. Hamara shareer tab thanda hota hai jab paseena evaporate hota hai, aur nam hawa mein yeh dheere evaporate hota hai, isliye hum chipchipa aur zyaada garam mehsoos karte hain.

Precipitation

Jab nam hawa upar uthti hai, to thandi hoti hai. Thandi hawa utni water vapour nahi rakh sakti, isliye jab hawa saturated ho jaati hai to extra vapour condense hokar chhoti droplets ya ice crystals ban jaati hai, aur baadal bante hain. Jab yeh itne bhaari ho jaate hain ki upar nahi tik sakte, to gravity inhe precipitation (वर्षण) ke roop mein neeche le aati hai. Yeh kai roopon mein aata hai:

  • Rain: liquid paani ki boondein, sabse aam roop.
  • Drizzle: bahut baareek boondein jo dheere girti hain.
  • Snow: ice crystals jo aapas mein chipak kar flakes ban jaate hain.
  • Sleet: rain aur snow ka mix, ya baarish ki boondein jo girte-girte jam kar ice pellets ban jaati hain.
  • Hail: oonche thunderclouds ke andar layer-dar-layer bane barf ke gole.

Rain, jo sabse aam roop hai, hawa ko thanda karti hai, nadiyon aur talaabon ko bharti hai, aur zameen mein reesakar groundwater ko phir se bharti hai, jisse zyaadatar kuon aur tube-wells ko paani milta hai. Jis jagah lambe samay tak kam baarish hoti hai, wahan dry climate ban jaata hai. Precipitation kahan aur kab hoga, yeh nam hawa laane wali winds, hawa ko upar uthne par majboor karne wale mountains, aur season par nirbhar karta hai. Western Ghats ki windward side par base Mumbai ko Pune se kai guna zyaada baarish milti hai, jo unke theek us paar hai.

Definition
Precipitation

Baadalon se zameen par kisi bhi roop mein girne wala paani: rain, drizzle, snow, sleet ya hail.

Atmospheric pressure

Hawa ka wazan hota hai, aur har surface par uske dabaav ko air pressure ya atmospheric pressure (वायुदाब) kehte hain. Weather reports ise hectopascals (hPa) mein naapti hain; sea level par iska average lagbhag 1013 hPa hai. Pahaad par chadho to tumhare upar kam hawa hoti hai, isliye pressure tezi se girta hai. Lagbhag 5.5 km upar yeh sea level ki value ka sirf aadha reh jaata hai, isiliye sabse oonchi chotiyon par chadhne wale climbers aksar oxygen saath le jaate hain.

Zameen par bhi pressure jagah-jagah alag hota hai, mainly temperature ki wajah se (Fig. 3.5). Garam zameen ke ek hisse ke upar hawa garam hoti hai, failti hai, halki hoti hai aur upar uthti hai, jisse surface par low pressure ban jaata hai. Upar uthti hawa thandi hoti hai, isliye low pressure aksar baadal aur baarish laata hai. Thande ilaake ke upar hawa ghani hoti hai aur neeche baithti hai, jisse high pressure banta hai. Neeche baithti hawa garam aur sookhi ho jaati hai, isliye high pressure ka matlab aam taur par saaf, dhoop wala aasmaan hota hai.

4/4Hawa zameen ke saath-saath high se low ki taraf behti hai: yahi wind hai.

Fig. 3.5Garam hawa upar uthkar low pressure chhodti hai; thandi hawa neeche baith kar high pressure banati hai; wind high se low ki taraf chalti hai.NCERT Fig. 3.7 · p. 45

Zameen ka side view jismein left par ek thanda ilaaka aur right par ek garam ilaaka hai, aur Sun garam side par chamak raha hai. Step 2 mein teen arrows garam zameen ke upar garam hawa ko uthte dikhate hain, ek bada L surface par low pressure dikhata hai, aur upar baarish wala ek baadal banta hai. Step 3 mein dashed arrows thandi zameen ke upar thandi hawa ko baithte dikhate hain, ek bada H high pressure dikhata hai, aur upar ke aasmaan par clear likha hai. Step 4 mein zameen ke saath ek mota arrow, jis par wind likha hai, left ke high se right ke low ki taraf jaata hai, aur bahut upar ek dashed arrow hawa ko low side se waapas high side tak le jaata hai.

Chalti hawa hamesha high pressure se low pressure ki taraf jaati hai, bilkul waise jaise valve kholne par hawa bhari cycle tube se tezi se bahar nikalti hai. Weather maps ise isobars se dikhate hain, yaani aisi lines jo barabar pressure wali jagahon ko jodti hain. Kyunki Earth ghoomti hai, isliye chalti hawa high se low tak seedhi nahi jaati; woh ek taraf mud jaati hai aur pressure centres ke chaaron taraf ghoomti hai. Air pressure ke baare mein tumne Grade 8 Science (Curiosity) mein aur padha tha.

Wind

Wind (पवन) high pressure wale ilaake se low pressure wale ilaake ki taraf chalti hawa hai. Thodi doori par pressure ka farq jitna bada hoga, wind utni tez chalegi. Halki wind patang ko uski dor par kheenchti hai aur geele farsh ko jaldi sukha deti hai. Tez wind nariyal ke pedon ko jhuka deti hai aur darwaazon ko zor se band kar deti hai, aur cyclone tin ki chhaton ko ukhaad sakta hai aur bijli ke khambhon ko tod sakta hai.

Winds ko compare karne ke liye sailors aur weather services Beaufort scale use karte hain, jise sabse pehle British naval officer Francis Beaufort ne 1805 mein banaya tha. Ismein 13 steps hain, 0 (calm) se 12 (hurricane force) tak, aur har step speeds ki ek range aur dikhne wali cheezon se juda hai (Table 3.2).

Table 3.2Beaufort wind scale ke kuch stepsNCERT Table 3.1 · p. 46
NaamSpeed (km/h)Tumhe kya dikh sakta hai
Gentle breeze12–19Pattiyan aur patli tehniyan hilti rehti hain; halka jhanda fadfadaata hai.
Fresh breeze29–38Pattiyon wale chhote ped jhoolne lagte hain; talaabon par lehren chhoti waves ban jaati hain.
Gale62–74Pedon se tehniyan toot jaati hain; hawa ke khilaaf chalna mehnat ka kaam hai.
Hurricane force118 aur usse zyaadaBhaari, door-door tak nuksaan, jaise sabse tez cyclones mein.

3.2.2 Land aur Sea Breezes

Puri ya Chennai ke beach par poora din bitao to tum wind ko side badalte mehsoos karoge. Iski wajah yeh hai ki land paani se kahin zyaada jaldi garam aur thanda hota hai. Sun sirf ret aur mitti ki ek patli upari layer ko garam karta hai. Sunlight samundar mein gehraai tak jaati hai, aur paani lagaataar mixing karta rehta hai, jisse heat ek bade volume mein fail jaati hai.

Der subah tak land sea se zyaada garam ho jaata hai (Fig. 3.6). Land ke upar ki hawa upar uthti hai, wahan pressure girta hai, aur sea se thandi hawa andar aati hai: yeh hai sea breeze. Yeh aam taur par dopahar mein sabse tez hoti hai, aur yahi ek wajah hai ki garmiyon mein coastal cities andar ke towns se zyaada sehne laayak lagti hain. Sunset ke baad land apni heat jaldi kho deta hai aur jald hi paani se thanda ho jaata hai. Ab pressure sea ke upar kam hota hai, aur hawa land se bahar ki taraf behti hai: yeh hai land breeze. Raat mein temperature ka farq kam hota hai, isliye land breeze aam taur par halki hoti hai. Yeh local winds milkar coastal climates ko moderate rakhti hain.

1/2Land sea se garam: sea breeze land ki taraf chalti hai.

Fig. 3.6Din mein breeze sea se andar aati hai; raat mein land se bahar jaati hai.NCERT Fig. 3.8 · p. 46

Ek coast ka side view jismein left par sea aur right par pedon wala land hai. Din wale step mein Sun chamakta hai, land par warmer aur sea par cooler likha hai, sea ke upar H aur land ke upar L hai, sea breeze likha ek mota arrow surface ke saath sea se land ki taraf chalta hai, aur dashed arrows ek loop poora karte hain: land ke upar uthna, bahut upar sea ki taraf waapas jaana, aur sea ke upar neeche baithna. Raat wale step mein Sun ki jagah Moon aata hai, labels badal jaate hain to sea warmer aur land cooler ho jaata hai, L sea ke upar aur H land ke upar chala jaata hai, land breeze likha mota arrow land se sea ki taraf hota hai, aur dashed loop ulti disha mein chalta hai.

Quick check
3 mein se 1
Sunlight ki wahi beam poles ke paas zameen ko equator ke mukaable kam garam kyun karti hai?
Answer dekho

Answer (B) Tirchhi beam bade area par fail jaati hai

Tirchhi beam apni energy ko bade hisse par faila deti hai, isliye har square metre ko kam milti hai. Sun se doori ka farq itna chhota hai ki uska koi asar nahi padta.

3.2.3 Graph par Climate

Kisi jagah ka climate ek nazar mein kaise dekh sakte hain? Geographers ek climograph banate hain, ek hi chart jo har mahine ka average temperature ek line se aur har mahine ki average rainfall bars se dikhata hai. Yeh averages kai saalon ke records se aate hain; Table 3.3 ke paanch stations 1991 se 2020 tak ke 30 saal use karte hain.

Table 3.3Paanch Indian stations par average monthly temperature (°C) aur rainfall (cm), 1991–2020NCERT Table 3.3 · p. 58
PanajiHyderabadBhubaneswarAhmedabadGuwahati
°Ccm°Ccm°Ccm°Ccm°Ccm
Jan26.30.122.80.822.21.320.10.117.41.1
Feb26.60.025.40.925.62.422.80.120.01.8
Mar27.90.128.81.729.22.127.70.123.55.2
Apr29.50.531.43.031.44.331.90.225.717.8
May30.17.733.23.432.010.634.50.627.325.8
Jun27.887.029.711.030.720.733.37.928.730.9
Jul26.895.627.215.829.037.929.832.129.328.3
Aug26.957.226.420.528.638.928.823.729.526.9
Sep27.129.826.814.728.829.329.312.328.618.6
Oct28.016.026.211.927.717.528.81.226.710.7
Nov28.12.124.12.125.13.425.10.222.81.0
Dec27.00.222.20.422.20.521.60.119.00.5
Saal27.7296.327.086.227.7168.927.878.624.9168.6

Har station ka latitude aur oonchaai: Panaji 15°29′ N, 58 m; Hyderabad 17°27′ N, 530 m; Bhubaneswar 20°15′ N, 45 m; Ahmedabad 23°04′ N, 55 m; Guwahati 26°06′ N, 54 m. 'Saal' wali row average temperature aur total rainfall (round kiye gaye monthly values ka jod) deti hai. Source: in stations ke 1991–2020 ke monthly climate normals, jinhe Japan Meteorological Agency ke Tokyo Climate Center ne Indian station reports se compile kiya; rainfall ko millimetres se centimetres mein badla gaya hai.

4/4Panaji saal bhar garam, monsoon mein bahut geela aur December se April tak sookha rehta hai.

Fig. 3.7Climograph har mahine ka temperature ek line se aur rainfall bars se dikhata hai.NCERT Fig. 3.14 · p. 59

Panaji, Goa ka ek chart jo 1991–2020 ke averages use karta hai, neeche January se December tak mahine, left axis par 0 se 35 degrees Celsius tak temperature aur right axis par 0 se 100 centimetres tak rainfall. Step 1 mein sirf khaali axes hain. Step 2 mein rainfall bars judte hain: December se April tak lagbhag kuch nahi, May mein lagbhag 8 cm, phir June mein 87 cm, July mein 96 cm aur August mein 57 cm ke bahut oonche bars, jo September mein 30 cm aur October mein 16 cm tak gir jaate hain. Step 3 mein temperature ki line judti hai, jo saal bhar lagbhag 26 aur 30 degrees ke beech rehti hai aur May mein sabse oonchi hoti hai. Step 4 mein notes judte hain: sabse geela mahina July, saal bhar 26 se 30 degrees, aur December se April tak sookha.

Example

Panaji ka climograph banao aur padho

Table 3.3 ki Panaji wali rows se ek climograph banao, aur do sentences mein Panaji ka climate describe karo.

Pehle khud try karo. Phir solution ek-ek step karke kholo.

Quick check
2 mein se 1
Kaun sa statement weather ki jagah climate ko describe karta hai?
Answer dekho

Answer (C) Chennai ko apni zyaadatar baarish October se December tak milti hai

Kisi jagah ko aam taur par kahan aur kab baarish milti hai, yeh lambe samay ka average hai, isliye yeh climate hai. Baaki teen khaas dinon ya hafton ko describe karte hain: weather.

3.3 India mein Seasons

Apne town ke kisi bade-buzurg se poocho ki aam ke pehle baur kab aate hain, pehli badi baarish kab hoti hai ya raat mein pehli baar kambal kab chahiye hota hai. Woh har saal lagbhag wahi hafte batayenge. Saal ka har woh hissa jismein ek jaisa weather hafton ya mahinon tak baar-baar aata rehta hai, ek season hai.

India ka climate tropical monsoon type ka hai. Saal ke zyaadatar hisse mein yeh garam rehta hai, jismein monsoon winds ka laaya ek main baarish ka season hota hai aur beech mein lambe sookhe daur. India Meteorological Department (IMD) chaar seasons maanta hai, jo Table 3.5 mein bataye gaye hain.

Table 3.5India ke chaar seasons
SeasonAam mahineKaisa hota hai
WinterDecember se April ki shuruaat takDecember aur January sabse thande mahine hain. North-west mein raatein paale wali hoti hain, jabki south mein halki thand rehti hai.
Summer (pre-monsoon)April se June; north-west mein July takGaram aur zyaadatar sookha. West aur south mein April sabse garam mahina hai, north mein May.
Monsoon (aage badhta monsoon)June se SeptemberNam south-west winds poore desh par chhaa jaati hain aur saal ki zyaadatar baarish laati hain.
Post-monsoon (lautta monsoon)October se DecemberNorth se baarish hat jaati hai aur wahan aasmaan saaf ho jaata hai; south-east coast par bhaari baarish hoti hai.

Table mein mahine overlap karte hain kyunki seasons fixed dates par switch on-off nahi hote, aur alag-alag regions mein alag-alag samay par pahunchte hain. Phir bhi apne weather records ke liye IMD mahinon ke fixed blocks use karta hai (Fig. 3.8). Winter January–February hai, pre-monsoon March–May, monsoon June–September aur post-monsoon October–December. Thande Himalayan states mein log alag se spring aur autumn bhi mehsoos karte hain.

3/3IMD ke records chaar seasons use karte hain; Varṣhā monsoon ke andar aati hai.

Fig. 3.8Do-do mahine ke chhah paramparik ṛtus, aur IMD ke records mein use hone wale chaar seasons.NCERT Table 3.2 · p. 48

Baarah columns January se December tak ke mahinon ko dikhate hain. Step 1 mein sirf mahine hain. Step 2 mein paramparik ṛtus ke liye do-do mahine ke chhah blocks ki ek row judti hai: January aur February mein Śhiśhira, March aur April mein Vasanta, May aur June mein Grīṣhma, July aur August mein Varṣhā, September aur October mein Śharad, aur November aur December mein Hemanta. Step 3 mein IMD records ke chaar seasons ki doosri row judti hai: January aur February mein winter, March se May tak pre-monsoon, June se September tak monsoon, aur October se December tak post-monsoon.

Flash cards · 6

Chhah ṛtus

1 / 6
Quick check
3 mein se 1
Har season ko un mahinon se match karo jo IMD apne weather records mein uske liye use karta hai.

Left mein koi item tap karo, phir right mein uska match.

Answer dekho
Answer
  • Winter : January–February
  • Pre-monsoon : March–May
  • Monsoon : June–September
  • Post-monsoon : October–December
IMD ka record-keeping saal winter (Jan–Feb), pre-monsoon (Mar–May), monsoon (Jun–Sep) aur post-monsoon (Oct–Dec) se chalta hai.

3.4 Monsoon

Hamara shabd monsoon (मानसून) mausim se aaya hai, jo season ke liye Arabic shabd hai. Arab traders ise Arabian Sea ke upar seasons ke saath disha badalne wali hawa ke liye use karte the. Sadiyon tak paal wale jahaaz us samundar ko tabhi paar kar paate the jab hawa sahi ho, isliye sailors India ke ports tak apni yatraon ka samay isi se tay karte the. India ke climate ko banane wali saari forces mein isse zyaada zaroori koi nahi.

Definition
Monsoon

Ek wind system jo seasons ke saath apni disha ulat deta hai, jisse ek geela season aur ek sookha season milta hai.

ExampleIndia mein garmiyon mein wind south-west se aur sardiyon mein north-east se chalti hai.

3.4.1 South-west Monsoon

South-west monsoon, ya summer monsoon, June se September tak chalta hai. Yeh sea breeze wale idea par hi chalta hai, yaani land aur water ka asmaan garam hona, lekin poore subcontinent ke scale par (Fig. 3.9). April aur May mein Indian landmass tapta hai, aur desh ke north-west ke upar low pressure ka ek bada area ban jaata hai. Indian Ocean dheere garam hota hai aur apekshaakrit thanda rehta hai, isliye uske upar pressure zyaada hota hai. Hawa ocean ke high se land ke low ki taraf behti hai. Hazaaron kilometre garam samundar paar karte hue yeh bahut saari water vapour jamaa karti hai aur garam, nam winds ke roop mein south-west se India pahunchti hai.

2/4Nam winds sea se andar aati hain aur hills par upar uthti hain, jisse bhaari baarish hoti hai.

Fig. 3.9Summer: garam land ke upar low pressure nam sea winds ko andar kheenchta hai. Winter: thande land se sookhi winds bahar chalti hain, lekin jo sea paar karti hain woh aage ke coast par baarish laati hain.

Ek side view jismein bilkul left par coast ki ek chhoti patti, beech mein sea aur right par ek hill ke saath bada landmass hai. Step 1, summer: Sun chamakta hai, land par hot aur low pressure ke liye L likha hai, aur sea par cooler aur high pressure ke liye H likha hai. Step 2 mein moist winds likha ek mota arrow judta hai jo sea se hill ki taraf upar chalta hai, aur hill ke upar ek baadal aur bhaari baarish hai. Step 3, October se winter: land par cold aur H likha hai aur sea par warmer aur L, aur dry winds likha ek dashed arrow land se sea ki taraf chalta hai. Step 4 mein wind sea ke paar aage badhti dikhti hai, boondon ke roop mein dikhayi nami uthati hai, aur left ke chhote coast par baarish ka baadal laati hai, jis par likha hai ki coast ko baarish milti hai.

Jab yeh winds land se milti hain, aur khaas kar jab Western Ghats jaisi hills unhe upar uthne par majboor karti hain, to hawa thandi hokar apni nami bhaari baarish ke roop mein gira deti hai. Ek shaakha Arabian Sea se west coast par aati hai. Doosri Bay of Bengal paar karke north-east India ki taraf jaati hai aur phir Ganga plains ke saath west ki taraf mud jaati hai. India ki saalaana baarish ka lagbhag teen-chauthai hissa in chaar mahinon mein girta hai. June se September ke liye IMD ka long-term average 87 cm hai, poore saal ke lagbhag 116 cm mein se (1971–2020 averages).

Monsoon poore desh mein ek saath nahi pahunchta. Aam taur par yeh lagbhag 1 June ko Kerala mein shuru hota hai aur phir north aur west ki taraf badhta hai, aur lagbhag 8 July ko desh ke door north-west tak pahunchta hai. Yeh lagbhag ulte kram mein lautta hai, sabse pehle lagbhag 17 September ko western Rajasthan chhodta hai, aur sabse aakhir mein lagbhag 15 October tak south se jaata hai (Fig. 3.10). Yeh IMD ki 'normal' dates hain, jo lambe records se 2020 mein revise ki gayi; kisi ek saal mein asli dates ek-do hafte pehle ya baad mein ho sakti hain.

3/3Isliye Kerala mein baarish ka season lagbhag 136 din chalta hai lekin western Rajasthan mein sirf lagbhag 71 din.

Fig. 3.10IMD ki normal dates (2020 mein revised): monsoon south mein sabse pehle aata hai aur sabse lamba rukta hai, aur north-west mein sabse aakhir mein pahunchta hai.NCERT Figs. 3.10–3.11 · p. 50

Ek chart jismein neeche June se October tak mahine hain aur Kerala, Mumbai, Ahmedabad, Delhi aur western Rajasthan ke liye paanch rows hain. Step 1 mein har row mein normal onset date ek dot se dikhayi gayi hai: Kerala ke liye 1 June, Mumbai ke liye 11 June, Ahmedabad ke liye 21 June, Delhi ke liye 27 June aur western Rajasthan ke liye 8 July, isliye neeche jaate hue dots right ki taraf khiskte hain. Step 2 mein normal withdrawal dates ke liye diamonds judte hain: Kerala ke liye 15 October, Mumbai ke liye 8 October, Ahmedabad ke liye 30 September, Delhi ke liye 25 September aur western Rajasthan ke liye 17 September, isliye yeh neeche jaate hue left ki taraf khiskte hain. Step 3 mein har jode ko ek bar se joda gaya hai jo dikhata hai ki monsoon kitne din rukta hai: Kerala mein 136 din, Mumbai mein 119, Ahmedabad mein 101, Delhi mein 90 aur western Rajasthan mein 71.

3.4.2 North-east Monsoon

October se pattern palat jaata hai. Ab land sea se jaldi thanda hota hai, isliye northern India ke thande plains ke upar pressure badhta hai aur south ke garam samundaron ke upar girta hai. Winds land se bahar ki taraf, north-east se, chalti hain, isiliye ise north-east monsoon ya winter monsoon kehte hain; yeh lagbhag October se February tak chalta hai. Land ke upar se aayi hawa sookhi hoti hai, isliye in mahinon mein India ke zyaadatar hisse ko kam baarish milti hai.

Iska apvaad south-east hai. Bay of Bengal paar karne wali winds raaste mein nami utha leti hain aur use Tamil Nadu, coastal Andhra Pradesh aur Karnataka ke kuch hisson par baarish ke roop mein gira deti hain. Jaise, Chennai ko sabse bhaari baarish October aur November mein milti hai, jab desh ka zyaadatar hissa sookh raha hota hai. In ilaakon ke liye winter monsoon hi main baarish ka season hai.

Compare

Do monsoons ki tulna

South-west (summer) monsoon

  • June se September
  • Garam land ke upar low pressure, ocean ke upar high
  • Nam winds sea se land ki taraf chalti hain
  • India ki zyaadatar baarish laata hai

North-east (winter) monsoon

  • Lagbhag October se February
  • Thande land ke upar high pressure, sea ke upar low
  • Zyaadatar sookhi winds land se sea ki taraf chalti hain
  • Baarish mainly south-east coast par

3.4.3 Monsoon aur Hamari Zindagi

June mein Vidarbha ke kisi kheti wale gaon ki kalpana karo. Sab aasmaan ki taraf dekh rahe hain. Jaise hi pehli achhi baarish mitti ko bhigo deti hai, parivaar cotton, soybean aur tur jaisi kharif fasalein bote hain, aur aage ke sookhe mahinon ke liye gaon ka talaab aur kuen bharne lagte hain. India ke zyaadatar hisse mein monsoon saal ki main water supply hai. Towns mein iska asar sabziyon ke daam, hydroelectric dams par banne wali bijli aur khet mazdooron ke kaam mein dikhta hai. Teej aur Nag Panchami jaise tyohaar baarish ke season ke hain.

Monsoon ke tohfe hamesha naram nahi hote:

  • Kam samay mein bahut zyaada baarish floods aur landslides laati hai, jaisa Section 3.5.1 ki case study dikhati hai.
  • Kamzor ya der se aaya monsoon, ya uske beech lambe sookhe break, drought, fasal kharaab hona aur peene ke paani ki kami la sakte hain.
  • Gaon ke parivaar, jinka kaam aur kamaai kheti par nirbhar hai, baarish na hone par sabse zyaada prabhavit hote hain.
Quick check
4 mein se 1
South-west monsoon ko mainly kya chalata hai?
Answer dekho

Answer (B) Garmiyon mein land ka sea se jaldi garam hona

Garam landmass par low pressure banta hai jabki thande ocean par zyaada pressure hota hai, isliye ocean ki nam hawa andar aati hai. Asal mein Earth July ki shuruaat mein Sun se sabse door hoti hai.

3.5 Climate Change

Saal 2024 records ke 170 se zyaada saalon mein sabse garam tha. Earth ka climate pehle bhi badla hai, ice ages aur garam daur ke zariye jo hazaaron saal chale. Scientists ko ab jo baat pareshaan karti hai woh hai ki aaj ka badlaav kitni tezi se ho raha hai, aur uska main kaaran: insaani activity. Climate change ka matlab hai temperatures, rainfall, winds aur weather ke doosre patterns mein lambe samay ke badlaav. 1800s se bijli, transport aur industry ke liye coal, oil aur gas jalaane ne, aur jangal kaatne ne, hawa mein heat trap karne wali gases bhar di hain.

In greenhouse gases mein carbon dioxide, methane, nitrous oxide aur water vapour shaamil hain. Sunlight inke beech se aasaani se nikal kar zameen ko garam karti hai. Phir garam zameen heat chhodti hai, aur greenhouse gases uska kuch hissa absorb karke kuch waapas neeche bhej deti hain (Fig. 3.11). Bina kisi greenhouse gas ke Earth ek jama hua planet hoti. Dikkat yeh hai ki hum aur zyaada gases jodte ja rahe hain, isliye zyaada heat ruk jaati hai aur planet garam ho jaata hai.

4/4Fuels jalaane se aur gases judti hain, isliye zyaada heat rukti hai aur Earth garam hoti hai.

Fig. 3.11Greenhouse gases sunlight ko andar aane deti hain lekin zameen se nikalne wali kuch heat ko rok leti hain; zyaada gases jodne se zyaada heat rukti hai.

Ek scene jismein upar left mein Sun, aasmaan mein greenhouse gases likhi dots ki ek patti, ek building aur ek ped ke saath zameen, aur right mein Earth likha ek thermometer hai. Step 1 mein sunlight ke do mote arrows gas ki patti se guzar kar zameen tak jaate hain. Step 2 mein zameen se upar uthti heat ke lehardaar arrows judte hain; ek patti ke paar bahar nikal jaata hai aur ek uske andar ruk jaata hai. Step 3 mein patti se waapas neeche aate dashed lehardaar arrows judte hain, jin par some heat held likha hai, aur thermometer thoda upar chadhta hai. Step 4 mein dhuan chhodti factory ki chimney aur patti mein bahut saare aur gas dots judte hain, aur dashed arrows zameen par heat lautaate hain, aur thermometer aur upar chadhta hai.

India mein iske sanket hain zyaada baar aane wali aur zyaada tez heatwaves, kuch dinon par bahut bhaari baarish aur beech mein lambe sookhe gap, aur Himalaya mein sikudte glaciers. Badhta samundar Sundarbans jaise neeche coasts ke liye khatra hai. Duniya bhar mein jo species jaldi adapt nahi kar paatin, woh khatam ho rahi hain. Health, fasalon aur kamaai ka nuksaan un par sabse zyaada padta hai jinke paas sambhalne ke sabse kam saadhan hain: gareeb parivaar, baarish par nirbhar kisaan aur bahar kaam karne wale log. Mahilaon aur bachchon par aksar extra bojh padta hai, jaise jab unhe paani ke liye aur door chalna padta hai ya jab disasters ki wajah se schools band ho jaate hain.

Koi ek kadam is problem ko hal nahi kar sakta, lekin kai kadam milkar farq laate hain. Desh solar aur wind power jaisi renewable energy apna sakte hain, jangalon ko bacha aur badha sakte hain, aur saaf industries aur public transport bana sakte hain. Hum mein se har koi apna carbon footprint (कार्बन पदचिह्न) chhota kar sakta hai.

Definition
Carbon footprint

Koi vyakti, parivaar ya organisation jis tarah jeeta hai usse hawa mein judne wali saari greenhouse gases: use ki gayi bijli, ki gayi yatraayein aur khareedi gayi cheezein.

ExampleJo parivaar roz ki trips ke liye car chhod kar metro lene lagta hai, uska carbon footprint chhota ho jaata hai.

InteractiveMera carbon habits check

Roz ki aadaton par paanch sawaalon wala ek form: school jaana, fans, lights aur air conditioning, paani, khaana aur plastics. Har sawaal mein 1, 2 ya 3 points wali teen choices hain. Form ke neeche ek panel 15 mein se total score, ek rangeen bar, light se heavy footprint tak ek band, aur 1 point se zyaada score karne wali har aadat ke liye ek tip dikhata hai.

Fig. 3.12Wahi chuno jo tum aam taur par karte ho; score aur tumhari pledge ke ideas saath-saath update hote hain.

3.5.1 Case Study: 2025 ke Punjab Floods

August aur September 2025 ki shuruaat mein Punjab mein bhayanak floods aaye. State par aur Himachal Pradesh aur Jammu and Kashmir ki pahaadiyon par, jahan iski nadiyan shuru hoti hain, bahut bhaari monsoon baarish hui. Satluj, Beas aur Ravi, Ghaggar ke saath, khatarnaak levels tak chadh gayi. Woh embankments tod kar ya apne kinaaron se bahar nikal kar gaon, khet, sadkon aur pulon par fail gayi.

2 September tak state government ne saare 23 districts ko flood-affected ghoshit kar diya tha. 2–3 September ko report kiye gaye aankdon mein 30 maut aur lagbhag 3.5 lakh log prabhavit gine gaye. 1.48 lakh hectares se zyaada par khadi fasalein kharaab hui (Punjab government ke aankde, jo AIR News aur The Tribune ne report kiye). Agle dinon mein nuksaan aur badh gaya. Gurdaspur, Amritsar, Ferozepur, Fazilka aur Pathankot sabse zyaada prabhavit districts mein the. Kheton, gharon aur public property ka nuksaan hazaaron crore rupaye tak pahuncha.

Nuksaan itna bada kyun tha? Geographers do tarah ke kaaranon ko dekhte hain (Fig. 3.13).

Compare

2025 Punjab floods ke kaaran

Natural kaaran

  • Punjab aur upar ki pahaadiyon par bahut bhaari monsoon baarish
  • Western disturbances, yaani west se aane wale weather systems, ne extra baarish jodi
  • Sabse bhaari baarish se pehle hi nadiyan oonchi beh rahi thi
  • Pahaadiyon ka paani aur local baarish ek saath pahunche

Insaan ke banaye kaaran

  • Puraane, kamzor mitti ke embankments (dhūsī bāndh) toot gaye
  • Nadiyon ke paas bane gharon aur kheton ne flood ke paani ko failne ki kam jagah chhodi
  • River beds aur dams mein silt ne unki paani rakhne ki kshamata kam kar di
  • Kuch warnings der se aayi ya saaf samajh nahi aayi

4/4Paani bahar nikal kar floodplain par bane kheton aur gharon ko dubo deta hai.

Fig. 3.13Bhaari baarish nadi ko bhar deti hai; silt aur kamzor kinaare uski kshamata kam karte hain, aur nadi ke paas bane ghar paani ke raaste mein khade hote hain.NCERT Figs. 3.12–3.13 · p. 55

Beech mein ek river channel ka side view, jiske dono taraf mitti ka embankment hai, left mein floodplain par fasalein aur right mein nadi ke paas do ghar. Step 1 mein channel mein paani normal aur neeche hai. Step 2 mein bhaari baarish wala ek baadal judta hai, jis par heavy rain in the hills likha hai, aur paani lagbhag embankments ke top tak chadh jaata hai. Step 3 mein river bed ko bharti silt ki ek grey layer aur right wale embankment mein ek daraar dikhti hai, jis par old, weak bank likha hai. Step 4 mein paani dono embankments ke upar se nikal kar kheton mein aur gharon ke aas-paas fail jaata hai, jis par flooded likha hai.

Table 3.72025 ke floods ne Punjab ko kaise maara
Kaun ya kyaKya hua
KhetDhaan aur doosri fasalein harvest se sirf kuch hafte pehle kai din tak paani mein doobi rahi.
JaanwarGaayein, bhainsein aur murgiyan beemaar padi ya doob gayi; dairy aur poultry farms tabaah ho gaye.
Sadkein aur buildingsSadkon, pulon, border fencing aur public buildings ko nuksaan pahuncha.
HealthGande ruke hue paani se water-borne diseases ka khatra badha aur saaf-safaai mushkil ho gayi.
ParivaarJaanein gayi, aur hazaaron parivaar doobe gaon chhod kar relief camps mein gaye.
Quick check
4 mein se 1
Inmein se kaun si greenhouse gas nahi hai?
Answer dekho

Answer (C) Nitrogen

Nitrogen zameen se nikalne wali heat ko absorb nahi karti. Methane, carbon dioxide aur nitrous oxide karti hain, isliye woh greenhouse gases hain.
Recap

Summary aur key points

  1. Atmosphere gravity se tiki gases ki ek layer hai: lagbhag 78 % nitrogen, 21 % oxygen aur doosri gases ki thodi maatra, saath mein badalti rehne wali water vapour aur dust (Section 3.1.1).
  2. Iski paanch layers, troposphere, stratosphere, mesosphere, thermosphere aur exosphere, is baat se alag hoti hain ki height ke saath temperature kaise badalta hai (Section 3.1.2).
  3. Weather troposphere mein hota hai; stratosphere mein ozone layer hai; meteors mesosphere mein jalte hain; auroras aur radio reflection thermosphere ke hain.
  4. Weather ghanton ya dinon tak hawa ki haalat hai; climate 30 saal ya usse zyaada ka average hai (Section 3.2).
  5. Insolation, aur isliye temperature, equator se poles ki taraf kam hota hai, jisse torrid, temperate aur frigid zones bante hain (Temperature).
  6. Garam uthti hawa low pressure banati hai aur thandi baithti hawa high pressure; wind high se low ki taraf chalti hai (Atmospheric pressure).
  7. Land paani se jaldi garam aur thanda hota hai, jisse din mein sea breeze aur raat mein land breeze chalti hai (Section 3.2.2).
  8. Climograph kisi jagah ke monthly temperatures ko line se aur rainfall ko bars se dikhata hai (Section 3.2.3).
  9. India ka climate tropical monsoon hai jismein IMD ke chaar seasons hain; parampara chhah ṛtus ginti hai (Section 3.3).
  10. South-west monsoon India ki lagbhag teen-chauthai baarish laata hai; north-east monsoon south-east coast par barasta hai (Section 3.4).
  11. Fuels jalaane aur jangal kaatne se nikli greenhouse gases Earth ko garam kar rahi hain; hum mein se har koi apna carbon footprint kam kar sakta hai (Section 3.5).
  12. 2025 ke Punjab floods dikhate hain ki extreme rain aur insaani choices milkar bhaari baarish ko disaster kaise bana deti hain (Section 3.5.1).
Practice · 20 questions

Practice questions answers ke saath (NCERT “Questions aur activities”)

  1. Short answerMediumNCERT Questions aur activities Q1

    Dry air lagbhag 78 % nitrogen, 21 % oxygen aur 1 % doosri gases hai. Tum ise ek pie diagram mein dikhana chahte ho.

    1. Ek ya do sentences mein batao ki atmosphere kya hai aur use Earth ke aas-paas kya tikaye rakhta hai.

      Solution dikhao

      Atmosphere mili-juli gases ki woh layer hai jo Earth ko ghere hue hai. Earth ki gravity use surface ki taraf kheenchti hai aur space mein bhatakne se rokti hai.

    2. Nitrogen wale slice ka angle kitne degrees hona chahiye?

      °
      Answer dekho

      Answer 280.8 °

      0.78 × 360° = 280.8°.

    3. Oxygen wale slice ka angle kitna hona chahiye?

      °
      Answer dekho

      Answer 75.6 °

      0.21 × 360° = 75.6°, jisse baaki saari gases ke liye 3.6° bachta hai.

    4. Bache hue 1 per cent mein se do gases ke naam batao, aur samjhao ki is diagram mein water vapour kyun nahi dikhayi gayi.

      Solution dikhao

      Argon (lagbhag 0.93 %) aur carbon dioxide (lagbhag 0.04 %); neon, helium aur ozone bhi hain. Water vapour ko chhoda gaya hai kyunki uski maatra jagah-jagah lagbhag zero se lekar lagbhag 4 % tak badalti hai, isliye diagram dry air dikhata hai.

  2. DiagramMediumNCERT Questions aur activities Q2

    Zameen se space tak atmosphere ke structure ka ek labelled diagram banao. Paanchon layers ko kram se dikhao, har boundary ki lagbhag height aur har layer ki ek khaasiyat bhi.

    Solution dikhao

    Tumhare diagram mein neeche se upar yeh dikhna chahiye:

    1. Troposphere: average mein 0 se lagbhag 12 km (poles par 8 km, equator par 18 km); baadal aur weather; height ke saath temperature girta hai. Boundary: tropopause.
    2. Stratosphere: lagbhag 50 km tak; ozone layer (lagbhag 15–35 km); shaant hawa, iske base ke paas jet aircraft. Boundary: stratopause.
    3. Mesosphere: lagbhag 80 km tak; meteors jal jaate hain; iske top ke paas sabse thandi hawa. Boundary: mesopause.
    4. Thermosphere: lagbhag 80 se 700 km; ionosphere radio waves ko reflect karta hai; auroras; temperature tezi se badhta hai.
    5. Exosphere: lagbhag 700 km ke upar; bahut patli hawa; halki gases space mein nikal jaati hain.
  3. Quick answerEasyNCERT Questions aur activities Q3

    India Meteorological Department ke maane chaar seasons ko kram se lagao, us season se shuru karke jismein January aata hai.

    1. Monsoon
    2. Winter
    3. Summer (pre-monsoon)
    4. Post-monsoon
    Answer dekho
    Answer
    1. Winter
    2. Summer (pre-monsoon)
    3. Monsoon
    4. Post-monsoon
    Winter, summer (pre-monsoon), monsoon (aage badhta monsoon) aur post-monsoon (lautta monsoon).
  4. Short answerMediumNCERT Questions aur activities Q4

    Tumhara dost kehta hai, 'Zameen ke har square metre ke upar ki hawa ka wazan lagbhag 10 tonnes hai. Hum to pichak jaane chahiye!' Lagbhag 40 words mein samjhao ki hume yeh pressure mehsoos kyun nahi hota.

    Solution dikhao

    AnswerHawa hum par har direction se barabar dabaav daalti hai, aur hamare shareer ke andar ke fluids aur gases bhi utne hi pressure se bahar ki taraf dhakelte hain, isliye forces balance ho jaate hain.

    Air pressure hum par ek saath har taraf se lagta hai: upar, neeche aur side se. Hamare shareer ke andar blood, doosre fluids aur lungs ki hawa bhi utne hi zor se bahar ki taraf dabaav daalte hain. Andar aur bahar ke pressures balance ho jaate hain, isliye hume koi dabaav mehsoos nahi hota. Pressure tabhi pata chalta hai jab woh jaldi badalta hai, jaise utarte aeroplane mein kaan pop karte hain.

  5. Short answerEasyNCERT Questions aur activities Q5

    Lambi doori ke aeroplanes oonchaai par udte hain, troposphere ke top ke paas ya lower stratosphere mein. Stratosphere ki kaun si khaasiyat use udne ke liye theek banati hai?

    Solution dikhao

    Aeroplanes stratosphere mein (ya uske theek neeche) udte hain kyunki yeh baadalon, toofaanon aur doosri weather ki gadbad se lagbhag mukt hai. Hawa shaant rehti hai, isliye flight smooth aur safe hoti hai.

  6. Long answerMediumNCERT Questions aur activities Q6

    Inke beech farq batao.

    1. Troposphere aur stratosphere

      Solution dikhao
      Table 3.8
      TroposphereStratosphere
      Sabse nichli layer, average mein 0 se lagbhag 12 kmTroposphere ke upar, lagbhag 50 km tak
      Height ke saath temperature girta haiIske upari hisse mein height ke saath temperature badhta hai
      Lagbhag saari water vapour, baadal aur weather yahin hainLagbhag koi baadal ya toofaan nahi; shaant hawa
      Hum yahin rehte aur saans lete hainIsmein ozone layer hai jo ultraviolet rays absorb karti hai

    2. South-west monsoon aur north-east monsoon

      Solution dikhao
      Table 3.9
      South-west monsoonNorth-east monsoon
      June se September (summer)Lagbhag October se February (winter)
      Garam land ke upar low pressure, ocean ke upar highThande land ke upar high pressure, sea ke upar low
      Nam winds sea se land ki taraf chalti hainZyaadatar sookhi winds land se sea ki taraf chalti hain
      India ki zyaadatar baarish laata haiBay of Bengal paar karne ke baad mainly Tamil Nadu, coastal Andhra Pradesh aur Karnataka ke kuch hisson mein baarish laata hai
  7. DiagramMediumNCERT Questions aur activities Q7, 7.1

    Table 3.3 ka station data use karo.

    1. Ahmedabad ka climograph banao.

      Solution dikhao

      Right par 0 se 35 cm ka rainfall axis (July mein 32.1 cm hai) aur left par 0 se 40 °C ka temperature axis lo. October se May tak chhote bars banao, phir June se September ke liye 7.9, 32.1, 23.7 aur 12.3 cm. Temperatures ko 20.1 °C (January) se 34.5 °C (May) tak plot karo, jo baarish ke mahinon mein lagbhag 29 °C tak girte hain, aur unhe ek line se jodo.

    2. Paanchon stations ko equator se sabse paas se sabse door ke kram mein lagao.

      1. Panaji
      2. Ahmedabad
      3. Bhubaneswar
      4. Guwahati
      5. Hyderabad
      Answer dekho
      Answer
      1. Panaji
      2. Hyderabad
      3. Bhubaneswar
      4. Ahmedabad
      5. Guwahati
      Latitude ke hisaab se: Panaji 15°29′ N, Hyderabad 17°27′ N, Bhubaneswar 20°15′ N, Ahmedabad 23°04′ N, Guwahati 26°06′ N.

    3. Kis station ki annual range of temperature sabse badi hai, yaani sabse extreme climate?

      Answer dekho

      Answer (C) Ahmedabad

      Ahmedabad: 34.5 − 20.1 = 14.4 °C. Uske baad Guwahati 12.1 °C, Hyderabad 11.0 °C, Panaji sirf 3.8 °C.

    4. Kis station ka climate sabse equable hai (sabse chhoti annual range)?

      Answer dekho

      Answer (D) Panaji

      Panaji ke sabse garam aur sabse thande mahine mein sirf 30.1 − 26.3 = 3.8 °C ka farq hai.
  8. Quick answerMediumNCERT Questions aur activities Q7.2

    Table 3.3 phir se use karo.

    1. February mein kaun se do stations sabse garam hain?

      Saare sahi options chuno
      Answer dekho
      Answer
      • (A) Panaji
      • (C) Bhubaneswar
      February: Panaji 26.6 °C, Bhubaneswar 25.6 °C, Hyderabad 25.4 °C, Ahmedabad 22.8 °C, Guwahati 20.0 °C.

    2. June mein kaun se do stations sabse garam hain?

      Saare sahi options chuno
      Answer dekho
      Answer
      • (C) Bhubaneswar
      • (D) Ahmedabad
      June: Ahmedabad 33.3 °C aur Bhubaneswar 30.7 °C; phir Hyderabad 29.7 °C, Guwahati 28.7 °C aur Panaji 27.8 °C.

    3. Monsoon ke lautne ke samay, October–December mein, kin do stations ko apni saalaana baarish ka sabse bada hissa milta hai?

      Saare sahi options chuno
      Answer dekho
      Answer
      • (B) Hyderabad
      • (C) Bhubaneswar
      October–December share: Hyderabad 14.4 ÷ 86.2 ≈ 17 %, Bhubaneswar 21.4 ÷ 168.9 ≈ 13 %, Guwahati lagbhag 7 %, Panaji lagbhag 6 %, Ahmedabad lagbhag 2 %.

    4. Ahmedabad ki saalaana baarish ka kitna percentage June se September tak girta hai?

      %
      Answer dekho

      Answer 96.7 %

      (7.9 + 32.1 + 23.7 + 12.3) ÷ 78.6 = 76.0 ÷ 78.6 ≈ 96.7 %.
  9. Short answerHardNCERT Questions aur activities Q7.3–7.4

    Table 3.3 aur jo tumne seekha hai uski madad se samjhao ki:

    1. Panaji ko Ahmedabad se lagbhag chaar guna baarish kyun milti hai.

      Solution dikhao

      Panaji (296.3 cm) west coast par Western Ghats ki talahati mein hai, monsoon ki nam Arabian Sea branch ke raaste mein. Hills hawa ko upar uthne par majboor karti hain aur lagbhag chaar mahine tak bhaari baarish girwati hain. Ahmedabad (78.6 cm) aur north mein aur andar ki taraf hai. Monsoon wahan der se pahunchta hai, jaldi chala jaata hai aur baarish laane wali kam winds laata hai.

    2. Guwahati ko monsoon aane se pehle, April aur May mein, 40 cm se zyaada baarish kyun milti hai.

      Solution dikhao

      April aur May mein (17.8 + 25.8 = 43.6 cm) north-east India ki bahut garam zameen Bay of Bengal se nam hawa kheenchti hai. Hawa upar uthkar pre-monsoon ke tez thunderstorms banati hai, isliye Guwahati ko monsoon se hafton pehle hi bhaari baarish mil jaati hai.

    3. Panaji ka temperature saal bhar mushkil se kyun badalta hai.

      Solution dikhao

      Panaji samundar ke kinaare hai, jo dheere garam aur thanda hota hai, aur sea breeze hawa ko naram rakhti hai. Yeh equator ke paas bhi hai, isliye dopahar ka Sun saal bhar ooncha rehta hai. Iski range sirf 3.8 °C hai, yaani equable climate.

    4. June se November tak Hyderabad Bhubaneswar se thanda kyun rehta hai, jabki Hyderabad aur south mein hai.

      Solution dikhao

      Hyderabad Deccan plateau par sea level se lagbhag 530 m upar hai, jabki Bhubaneswar coast ke paas sirf lagbhag 45 m upar hai. Troposphere mein height ke saath temperature girta hai, isliye oonchaai wala shehar thoda thanda hai (jaise August mein 28.6 °C ke mukaable 26.4 °C).

  10. Long answerHardNCERT Questions aur activities Q7.5

    Panaji, Hyderabad, Bhubaneswar, Ahmedabad aur Guwahati ke climates bahut alag hain. Table 3.3 ki madad se dikhao ki monsoon phir bhi unhe ek common pattern deta hai jo India ke climate ko ek karta hai.

    Solution dikhao

    Saalaana baarish 78.6 cm se 296.3 cm tak hai, aur temperature range 3.8 °C se 14.4 °C tak. Phir bhi paanchon stations monsoon ki tay ki hui ek hi lay share karte hain:

    • Saal ke beech mein baarish ka season: June–September Panaji ki 91 % aur Ahmedabad ki 97 % baarish laata hai. Yeh Bhubaneswar ki 75 %, Hyderabad ki 72 % aur Guwahati ki 62 % baarish laata hai.
    • Sookhi sardi: December se February tak har station par 5 cm se kam baarish hoti hai.
    • Baarish se pehle garmi: paanch mein se chaar stations May mein sabse garam hote hain, aur monsoon ke baadal aur baarish aane par temperature gir jaata hai.
    • Kheti aur zindagi ka ek calendar: in sab jagahon par buaai, fasal aur tyohaar monsoon ke aane aur lautne ke hisaab se chalte hain.

    Isliye monsoon ek dhaancha ban jaata hai jo poore desh ko ek common seasonal pattern deta hai, bhale hi har region ka climate alag ho.

  11. ActivityMediumNCERT Questions aur activities Q8

    India ke kam se kam chaar regions se gharon aur kapdon ki pictures jamaa karo. Har ek ke liye batao ki woh region ke climate ya landforms ke liye kaise theek hai.

    Solution dikhao

    Sample findings (tumhari pictures mein aur bhi ho sakte hain):

    • Kerala coast: dhalwaan tiled ya chhappar wali chhatein bhaari monsoon baarish ko gira deti hain; halke cotton ke kapde garam, humid hawa ke liye theek hain.
    • Western Rajasthan: moti mitti ya pathar ki deewarein aur chhoti khidkiyan garmi ko bahar rakhti hain; dheele, halke rang ke cotton kapde aur sar par kapda dhoop aur dhool se bachate hain.
    • Ladakh: mitti ki sapaat chhatein chal jaati hain kyunki baarish kam hoti hai; moti deewarein aur bhaari oonee kapde thand ko bahar rakhte hain.
    • Assam floodplains: bamboo ke khambhon par uthe ghar flood ke paani se upar rehte hain.
    • Himachal Pradesh: dhalwaan slate ya lakdi ki chhatein barf gira deti hain; oonee shawls aur topiyan logon ko garam rakhti hain.
  12. Quick answerEasy

    Troposphere aur stratosphere ke beech ki boundary ko kehte hain.

    Answer dekho

    Answer tropopause

    Tropopause troposphere ko dhakta hai; uske upar stratosphere aata hai.
  13. Quick answerEasy

    North-east wind north-east ki taraf chalti hai.

    Answer dekho

    Answer Galat

    North-east wind north-east se aati hai aur south-west ki taraf chalti hai.
  14. Quick answerMedium

    Assertion (A): Ek coastal city mein aam taur par garmi aur sardi ke temperatures ka farq usi latitude ki inland city se kam hota hai. Reason (R): Paani land ke mukaable dheere garam aur dheere thanda hota hai.

    Answer dekho

    Answer (A) A aur R dono true hain, aur R, A ki sahi explanation hai

    Dono true hain, aur samundar ka dheere garam aur thanda hona hi coastal temperatures ko moderate rakhta hai.
  15. Quick answerEasy

    Atmosphere ki kis layer mein auroras dikhte hain?

    Answer dekho

    Answer (D) Thermosphere

    Auroras lagbhag 80 aur 500 km ki oonchaai ke beech, thermosphere mein chamakte hain.
  16. Short answerMedium

    Case-based question. Yeh kaalpanik weather bulletin padho aur sawaalon ke jawab do.

    Thiruvananthapuram, 1 June. South-west monsoon Kerala par shuru ho gaya hai. Agle teen dinon mein kai jagahon par bhaari baarish ki ummeed hai, coast ke saath 40–50 km/h ki south-westerly winds aur 90 per cent se zyaada humidity ke saath. Machhuaron ko samundar mein na jaane ki salaah di jaati hai.

    1. Bulletin mein bataye gaye weather ke teen elements ke naam batao.

      Solution dikhao

      Precipitation (bhaari baarish), wind (south-westerly, 40–50 km/h) aur humidity (90 % se zyaada).

    2. Winds kis direction se chal rahi hain, aur woh apni nami kahan se laati hain?

      Solution dikhao

      Woh south-west se chalti hain, Arabian Sea aur Indian Ocean ke upar se, jahan unhone water vapour uthayi hai.

    3. Kerala par monsoon ka aana India ke doosre hisson ke kisaanon ke liye kyun zaroori hai?

      Solution dikhao

      Kerala par onset poore desh mein monsoon ke aage badhne ki shuruaat hai; yeh aam taur par agle hafton mein doosre regions tak pahunchta hai. Kisaan rice aur cotton jaisi kharif fasalon ki buaai in baarishon ke hisaab se plan karte hain.

    4. Machhuaron ko samundar mein na jaane ko kyun kaha ja sakta hai?

      Solution dikhao

      40–50 km/h ki winds Beaufort scale par 'strong breeze' ya 'near gale' ke kareeb hain. Yeh samundar ko ufaan par laati hain aur oonchi lehren uthaati hain, aur bhaari baarish se door tak dikhna kam ho jaata hai, isliye chhoti naavon ko khatra hota hai.

  17. DiagramMedium

    Map skill. India ke outline map par neeche di gayi cheezein mark karo aur unke label lagao.

    1. Woh state jahan south-west monsoon aam taur par sabse pehle pahunchta hai.

      Solution dikhao

      Kerala.

    2. South-east coast ke do states jinhe north-east monsoon se bhaari baarish milti hai.

      Solution dikhao

      Tamil Nadu aur Andhra Pradesh.

    3. Punjab ki teen nadiyan jinmein 2025 mein flood aaya.

      Solution dikhao

      Satluj, Beas aur Ravi (Ghaggar mein bhi flood aaya).

    4. Tropic of Cancer, aur koi bhi teen states jinse yeh guzarta hai.

      Solution dikhao

      Yeh Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Jharkhand, West Bengal, Tripura aur Mizoram se guzarta hai; inmein se koi bhi teen sahi hain.

  18. Long answerHard

    Samjhao ki land aur water ka asmaan garam hona sea breeze aur south-west monsoon dono ko kaise paida karta hai. Dono kin baaton mein milte-julte hain, aur kaise alag hain? (lagbhag 120 words)

    Solution dikhao

    Land paani se jaldi garam aur jaldi thanda hota hai. Jab land zyaada garam hota hai, to uske upar ki hawa upar uthkar low pressure chhodti hai, jabki thanda paani zyaada pressure banaye rakhta hai, isliye hawa sea se land ki taraf behti hai. Coast par dhoop wale dinon mein sea breeze isi tarah banti hai. South-west monsoon bhi garmiyon mein poore subcontinent par isi tarah banta hai, jab garam landmass ocean ki nam hawa ko andar kheenchta hai.

    Milte-julte: dono asmaan garmi se chalte hain aur dono sea se land ki taraf chalte hain. Jab land sea se thanda ho jaata hai to dono palat jaate hain (raat mein land breeze, sardi mein north-east monsoon). Alag: sea breeze kuch ghante chalti hai, andar sirf kuch kilometres tak pahunchti hai aur kam baarish laati hai. Monsoon mahinon tak chalta hai, poore desh ko cover karta hai aur India ki zyaadatar baarish laata hai.

  19. Long answerMedium

    Climate change ke teen kaaran aur teen asar batao, aur tumhara school apna carbon footprint kam karne ke liye kaun se teen kadam utha sakta hai, yeh sujhao.

    Solution dikhao
    • Kaaran: bijli, gaadiyon aur factories ke liye coal, oil aur gas jalaana; jangal kaatna, jo carbon store karte hain; kheti aur kachre se methane aur nitrous oxide ka emission.
    • Asar: zyaada baar heatwaves; zyaada bhaari floods aur lambe droughts; pighalte glaciers aur badhta samundar; health, fasalon aur kamaai ko nuksaan, khaas kar gareebon ko.
    • School ke kadam: chhat par solar panels lagao aur khaali kamron mein fans aur lights band karo. Paidal chalne, cycling aur shared buses ko badhaava do. Ped lagao, khaane ke kachre ka compost banao aur canteen mein single-use plastic se bacho.
  20. Short answerEasy

    Equator se poles ki taraf temperature aam taur par kam kyun hota jaata hai?

    Solution dikhao

    AnswerPoles ki taraf insolation kam hota hai kyunki Sun ki rays kam angle par padti hain aur utni hi energy ko bade area par faila deti hain.

    Equator ke paas Sun ki rays lagbhag seedhi padti hain aur apni energy ko ek chhote area par kendrit karti hain. Poles ki taraf woh tirchhi aati hain, isliye wahi energy kahin bade area par fail jaati hai aur har jagah ko kam heat milti hai. Tirchhi rays raaste mein zyaada hawa se bhi guzarti hain. Isliye insolation, aur uske saath temperature, equator se poles ki taraf kam hota jaata hai.

Apna NCERT exercise question dhoondo

Hamare practice questions ncert.ai ke liye likhe gaye hain aur NCERT exercises ko follow karte hain. Apni textbook ke question se match karne wala question dhoondo; uska answer uske saath hai.

Tumhari NCERT textbook meinYahan practice question
NCERT Questions aur activities Q1Practice Q1
NCERT Questions aur activities Q2Practice Q2
NCERT Questions aur activities Q3Practice Q3
NCERT Questions aur activities Q4Practice Q4
NCERT Questions aur activities Q5Practice Q5
NCERT Questions aur activities Q6Practice Q6
NCERT Questions aur activities Q7, 7.1Practice Q7
NCERT Questions aur activities Q7.2Practice Q8
NCERT Questions aur activities Q7.3–7.4Practice Q9
NCERT Questions aur activities Q7.5Practice Q10
NCERT Questions aur activities Q8Practice Q11

Quick check: MCQs

  1. 3.1.1 Atmosphere ki Composition3 questions
  2. 3.1.2 Atmosphere ka Structure4 questions
  3. 3.2.2 Land aur Sea Breezes3 questions
  4. 3.2.3 Graph par Climate2 questions
  5. 3.3 India mein Seasons3 questions
  6. 3.4.3 Monsoon aur Hamari Zindagi4 questions
  7. 3.5.1 Case Study: 2025 ke Punjab Floods4 questions
Glossary · 15

Key terms (English + Hindi)

air pressureवायुदाबvāyudāb
Kisi surface par hawa ke wazan ka dabaav; sea level par sabse zyaada aur oonchaai par kam.Chapter mein pehli baar yahan aaya →
altitudeऊँचाईūṁchāī
Mean sea level se oonchaai, jise zero maana jaata hai; aam taur par metres mein di jaati hai.Chapter mein pehli baar yahan aaya →
atmosphereवायुमंडलvāyumaṇḍal
Mili-juli gases ki layer jo Earth ko ghere hue hai aur gravity se apni jagah tiki hai.Chapter mein pehli baar yahan aaya →
carbon footprintकार्बन पदचिह्नkārban padchihn
Kisi vyakti, parivaar ya organisation ke jeene ke tareeke se hawa mein judne wali saari greenhouse gases.Chapter mein pehli baar yahan aaya →
climateजलवायुjalvāyu
Kisi jagah ya region ka lambe samay, aam taur par 30 saal ya usse zyaada, ka average weather aur uske aam utaar-chadhaav.Chapter mein pehli baar yahan aaya →
greenhouse gasग्रीनहाउस गैसgreenhouse gais
Carbon dioxide, methane, nitrous oxide ya water vapour jaisi gas, jo Earth se nikalne wali heat absorb karke uska kuch hissa waapas neeche bhejti hai.Chapter mein pehli baar yahan aaya →
humidityआर्द्रताārdratā
Hawa mein water vapour ki maatra.Chapter mein pehli baar yahan aaya →
insolationसूर्यातपsūryātap
Incoming solar radiation: Sun se aane wali energy jo Earth tak pahunchti hai.Chapter mein pehli baar yahan aaya →
monsoonमानसूनmānsūn
Ek wind system jo seasons ke saath disha ulat deta hai, jisse ek geela aur ek sookha season milta hai.Chapter mein pehli baar yahan aaya →
ozone layerओज़ोन परतozone parat
Stratosphere ka ek hissa, zyaadatar lagbhag 15–35 km upar, jismein ozone gas bahut hai jo nuksaandeh ultraviolet rays absorb karti hai.Chapter mein pehli baar yahan aaya →
precipitationवर्षणvarṣhaṇ
Baadalon se zameen par rain, drizzle, snow, sleet ya hail ke roop mein girne wala paani.Chapter mein pehli baar yahan aaya →
stratosphereसमतापमंडलsamtāpmaṇḍal
Troposphere ke upar ki layer, lagbhag 50 km tak; shaant aur lagbhag baadal-rahit, ismein ozone layer hai.Chapter mein pehli baar yahan aaya →
troposphereक्षोभमंडलkṣhobhmaṇḍal
Atmosphere ki sabse nichli layer, jahan hum rehte hain aur lagbhag saara weather hota hai; height ke saath thandi hoti jaati hai.Chapter mein pehli baar yahan aaya →
weatherमौसमmausam
Kisi jagah par thode samay, jaise ghanton ya dinon, ke liye atmosphere ki haalat.Chapter mein pehli baar yahan aaya →
windपवनpavan
High pressure wale area se low pressure wale area ki taraf chalti hawa.Chapter mein pehli baar yahan aaya →

Tum chapter ke end tak pahunch gaye