UPSC Prelims 2021 Answer Key | Science & Tech | UPSC 2021 Question Paper Solved | Paper Discussion

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  • Опубліковано 31 жов 2024

КОМЕНТАРІ • 127

  • @BharatKumar-vj5yy
    @BharatKumar-vj5yy 3 роки тому +30

    Question status moderate to difficult....no direct question. This time question was more deep explanation with basics. Some questions are pull from editorial concept. But very balance question. No Test series can make us profits.

  • @Civilservicesaspirants77
    @Civilservicesaspirants77 3 роки тому +19

    UPSC wants to select bookworm.

  • @priyanshupandey5325
    @priyanshupandey5325 3 роки тому +11

    The temperature of the pressure cooker will not depend on the intensity of the fire because each pressure cooker has a fixed boiling point ( Because lid is made keeping that in mind), if you give it more than that, it will come out as extra energy then it will depend only on lid and area so ans. 1 and 3 will correct according to myself

    • @BharatKumar-vj5yy
      @BharatKumar-vj5yy 3 роки тому +4

      Boiling point is same.... But transfer of heat and energy maximum due high flame... This is also come to my mind. So Ans 123..

    • @Baps978
      @Baps978 3 роки тому +1

      Bahoot harad…. Debatable…

    • @bansimangla7077
      @bansimangla7077 3 роки тому

      100% right bhai

    • @ronaldoningthoujam2495
      @ronaldoningthoujam2495 3 роки тому +2

      No, you can't say the temperature of the pressure cooker doesn't Depend on the temperature of the flame. I get what you are saying , once it reached the boiling point, we cannot increase the temperature of the cooker any further but before reaching the boiling point it is the temperature of the flame that brought the temperature of the cooker from zero to boiling point.

    • @Ankitgupta-nv6dr
      @Ankitgupta-nv6dr 3 роки тому +1

      I have put my rice in pressure cooker and kept atop a candle flame. Dont know why its taking forever to cook.

  • @manphulbudania2198
    @manphulbudania2198 3 роки тому +15

    Here is my take on cooker question:-
    If I go by general meaning of pressure cooker it would mean a cooker that uses pressure to cook the food.
    So it boils down to what all affects the pressure
    1) area of hole
    2) temp of flame (higher the flame temp higher is heat transfer, higher the pressure)
    3) weight of lid ( more weight=more pressure)
    So ans- D
    Let me know what u all think

    • @durgeshchoudhary492
      @durgeshchoudhary492 3 роки тому

      lid and valve is different thing or same

    • @kva9972
      @kva9972 3 роки тому +1

      My logic while attempting was exactly tge same. However no key that i looked so far claimed this as an answer

    • @ronaldoningthoujam2495
      @ronaldoningthoujam2495 3 роки тому

      But the question is about the factors influencing the temperature. I think that's why weight of the lid should not be considered here.
      If it was asked like how fast the food can be cooked , then we can consider the pressure ( the weight of the lid ).

    • @Ankitgupta-nv6dr
      @Ankitgupta-nv6dr 3 роки тому

      I don't think weight of lid will have effect because modern cookers have very light weight lids than normal one.. Even if we go by electric cooker, then weight of lid doesn't play any role. Rest like every time, upsc will again escape controversy by not releasing answer key.

  • @NishaKumari-zn9dh
    @NishaKumari-zn9dh 3 роки тому +7

    Thanks SIR now I'm in class12. I want to prepare of upsc with my 1st year graduation.
    But I'm very frightened from prelims specially in csat. So I watch your video in free time. It is very helpful 4 me . THANKS SIR 4 THIS🙏🏾🙏🏾🙏🏾🙏🏾

  • @jitnapakkahe7395
    @jitnapakkahe7395 3 роки тому +15

    11th 12th physics, chemistry and biology yahi he sara question ka base.

    • @mohdatif6651
      @mohdatif6651 3 роки тому +1

      Ayse he lgra h lekin aysa hota nhi

    • @kaushalgaur2131
      @kaushalgaur2131 3 роки тому

      Mai 11th mai hu pcb se science base pr hi h

  • @UPSCWITHTAPASTEWARI
    @UPSCWITHTAPASTEWARI 3 роки тому +15

    Upsc lucent ko v nhi chhoda😱...Unpredictable public service commission

  • @mayankchaudhary2578
    @mayankchaudhary2578 3 роки тому

    Sir end question ...speed of light is same only with one medium... When the medium is denser...the speed of light decrease...that also creates refractive index more....how it can be evaluated...because light travels in a straight line until there is any extra force...speed of light will be same in one medium... But when there is change in medium it differs... Also you can take black hole theory example

  • @Drhinasheikh2707
    @Drhinasheikh2707 Рік тому

    Virus ko artificial medium par culture nahi kar sakte. That doesn’t mean culture hi nahi kar sakte…. It just need a host, a living cell to multiply…. And that is y viruses are neighter living nor non living rather connecting link between them.

  • @AK-kj6yl
    @AK-kj6yl 3 роки тому +5

    On cooker questions I went with all
    And Othe science part is good as per the only IAS Answer key

  • @mr.perfect6540
    @mr.perfect6540 3 роки тому

    Mostly upsc becomes practical....u will get around 15 to 20 direct from practical where u need to apply ur logic to solve it rather it wont came by just studying books.....applications pe focus krna chahiye rather just doing everything from books by just rattafication or mug up.... Conceptual clarity must be there...then u will definitely able clear prelims

  • @PriyaPanchalInnosci
    @PriyaPanchalInnosci 3 роки тому +4

    Mera navratri ka vart hai...I watched abhi niyu vdo about significance of navratri vart, in that vdo he told we worship the mata becoz we get the dna mitochondria entirely from mother that is why mother or mata is worshipped..it's a coincidence that after watching the vdo I was sure about 2nd option...it means the question is asked from current affairs plus Indian mythology..I m glad to see this question..though m not an ias aspirant!

    • @saloni5415
      @saloni5415 3 роки тому

      It's mere coincidence UPSC just wants to be aware of all important facts everyday we should be a learner

    • @Shipra21
      @Shipra21 2 роки тому

      Dimaag kharab hai tera 😂

  • @AbhiKumar-gp9fe
    @AbhiKumar-gp9fe 3 роки тому +7

    Sir my gs paper was good but I lacked in csat sir 😭😭

  • @mahaswetadas805
    @mahaswetadas805 3 роки тому

    Sir optional ka kuch course he kya?..history

  • @akhiltej4604
    @akhiltej4604 Рік тому

    Nice initiative

  • @teamtrader407
    @teamtrader407 3 роки тому +8

    Sir sources quote krne se kuch nhi hoga... 2018 me buland darwaja ka question sab ne proof diye the. It was not even doubtful question. Phir bhi ans. Neither 1 nor 2 tha

  • @Ankitgupta-nv6dr
    @Ankitgupta-nv6dr 3 роки тому

    Sir i think led light can produce light 360, but its easier to engineer LEDs to produce focus light, which doesn't mean that it cannot be made to produce 360 if and equipment application demands

    • @RamSingh-qx1hb
      @RamSingh-qx1hb 2 роки тому

      ua-cam.com/video/76o2ZK5Xm6U/v-deo.html

  • @opjakhar648
    @opjakhar648 3 роки тому +2

    Jb aapko abhi tk confirm ni h fir ek student kaise solve kr skta h exam conditions m

  • @abhishekkatruwar5743
    @abhishekkatruwar5743 3 роки тому

    Sir in pressure cooker question ....temp of flame always remains same . Its the intensity of flame that matters.

  • @bishalkalita3388
    @bishalkalita3388 2 роки тому

    Science part was so easy.

  • @shubham-jt5th
    @shubham-jt5th 3 роки тому +3

    Sir prelium booster se koi bhi fasa yaa hamein source change krna pdega??

    • @shubham-jt5th
      @shubham-jt5th 3 роки тому

      @@KS-su6fb no bro..there were some questions..like bisphenol and 3-4 more related to science which were in news..

    • @shubham-jt5th
      @shubham-jt5th 3 роки тому

      @@KS-su6fb shayd is baar kuch nhi aya..pehle aata tha ..ab newspaper par hi rely krna pdega

  • @Dark.eveything
    @Dark.eveything 3 роки тому +4

    Sir speed of light also changes when medium change.there is solid reason for different refractive index in the space.
    I think light travel is the right answer.

    • @tnverma_india
      @tnverma_india 3 роки тому

      It is said for simplicity that light slows down in medium but photons themselves never slows down really..its a different mechanism...search about it ...

  • @rashmipal2050
    @rashmipal2050 2 роки тому

    Science padne ke liye kis class tk ki ncert pdni hogi

  • @indian8970
    @indian8970 3 роки тому +6

    Is bar sports se questions a gaya jo ajeeb tha...hamne to prepare hi nehi kiyatha

    • @Baps978
      @Baps978 3 роки тому +2

      Both statements were wrong…. Those who follow cricket can easily relate…

    • @vijaykumar-cp9hy
      @vijaykumar-cp9hy 3 роки тому +3

      Isi liye to unpredictable h, aur main epfo me isi wajah se bahar ho gya 185+ pr bhi. Jo prepare kiye usse km aa gya

    • @nidhipal251
      @nidhipal251 3 роки тому

      Bilkul yesa hi mere sath hua

  • @opjakhar648
    @opjakhar648 3 роки тому +1

    Aaj nhi kr skte bt aaj se 10 sal baad to may be Pasible

  • @swatantrayadav1438
    @swatantrayadav1438 3 роки тому

    12th genetic chapter ncert bio....

  • @narendradhanwani5001
    @narendradhanwani5001 3 роки тому +1

    Speed of light may be change as medium changes.

  • @letslearnmurtzaahmed7587
    @letslearnmurtzaahmed7587 3 роки тому

    think weight of cooker hoga... i.e material weight of cooker

  • @s.p.8548
    @s.p.8548 2 роки тому

    C can be correct answer

  • @mryellow805
    @mryellow805 3 роки тому

    Sir 36 wala aapka 100 percent galat hai iska keval b ya d none of these hoga kyonki mtritv prabhav me keval mitochondrial transfer hota hai aur first option me fertilisation k baad mitochondria transfer ki abhi tak koi technology nahi padhi hai sir ji

  • @opjakhar648
    @opjakhar648 3 роки тому +1

    Aaj ka ppr tough h jo pichle 2 sal se prep kr rha h

  • @deveshagrawal5766
    @deveshagrawal5766 3 роки тому +6

    it was very tough questions for me since i am not from SCI background! for me it was a setback!

  • @vikassarin1685
    @vikassarin1685 3 роки тому +1

    All flames have similar temperatures ranging from 175-210 celcius it depends on intensity of flame

  • @niharikamishra5475
    @niharikamishra5475 3 роки тому +4

    Sir virus ka culture bhi ho skta hai, corona bhi culture kiya gyaa thaa

    • @SHILPEE____ART
      @SHILPEE____ART 3 роки тому

      u can'nt sure.

    • @harikapotupureddi2513
      @harikapotupureddi2513 3 роки тому +2

      Yes WE can culture a virus
      I am Ann MBBS student
      From culture only the microbiologist says which organism it is

    • @niharikamishra5475
      @niharikamishra5475 3 роки тому

      @@harikapotupureddi2513 thanks

    • @manik9583
      @manik9583 3 роки тому

      @@harikapotupureddi2513 r u sure about this???bcz every amswer key says it can't be cultured..

    • @ashokyadav5632
      @ashokyadav5632 3 роки тому +1

      Biological weapons are artificially cultured.. Made in labs

  • @Monicapatil777
    @Monicapatil777 2 роки тому

    Imp topic suggest karo pleas 🙏

  • @Pragmatickk
    @Pragmatickk 3 роки тому +1

    Sir g..plz..revise Q 38..deeply...

  • @chitrasingh7225
    @chitrasingh7225 3 роки тому

    Speed of light varies with medium that's called refraction

    • @apurva8608
      @apurva8608 3 роки тому

      I also applied the same logic and found that only b options' info is correct but unfortunately for mapping distance of stellar objects we dont get any other medium than vacuum

    • @Ankitgupta-nv6dr
      @Ankitgupta-nv6dr 3 роки тому

      Last time i went to school we called it bending of light. And Speed of sound varied with medium, not light. Gosh, Science has advanced much.

  • @amanrajgupta5529
    @amanrajgupta5529 Рік тому

    8:39 D) hoga ! Reference : China 😂

  • @NaveenPalampur92
    @NaveenPalampur92 3 роки тому

    light travel in straight line sir . so it shouldbe the answer

  • @indian8970
    @indian8970 3 роки тому +1

    But sir India became the 1st country to culture virus in laboratory recently in news

  • @sirsuspicious_official
    @sirsuspicious_official 3 роки тому +1

    Thanks

  • @saketgautam7226
    @saketgautam7226 3 роки тому

    Sir velocity of light depend upon medium ..

  • @nitishkrsingh5497
    @nitishkrsingh5497 3 роки тому

    Science ka questions ,,,UPPSC previous year se aaya hai

  • @shaludubey1701
    @shaludubey1701 3 роки тому +1

    Bhyt hard paper tha aj ka sir

  • @BANTIKUMAR-de6mk
    @BANTIKUMAR-de6mk 3 роки тому

    Sir telegram nahi open ho raha hai

  • @parigupta3952
    @parigupta3952 3 роки тому +1

    pls sir iss pattern me prepare krne k liye source b share kijiye

  • @prasadbhagwat5458
    @prasadbhagwat5458 3 роки тому

    Very easy question

  • @DipeshTanwar
    @DipeshTanwar 3 роки тому +1

    11:36 question me led lamp k bare me poocha h , single led k bare me nahi poocha h .ua-cam.com/video/54wZ4x4s2xw/v-deo.html

  • @surajsisodiya831
    @surajsisodiya831 3 роки тому

    Sci. and tech ke mostly que. logical guess se hi correct hue h.

  • @Bujho1
    @Bujho1 3 роки тому +2

    sir wo three parent baby ka question hai na.. so only 2 correct

  • @ayushkumar-nb3xi
    @ayushkumar-nb3xi 3 роки тому

    Speed of light changes in different medium

    • @ronaldoningthoujam2495
      @ronaldoningthoujam2495 3 роки тому +1

      Yes, but there is hardly or no medium at all when we talk about astronomical distances ,( eg, distance between planets, stars ,etc.). So lightyear is used only in this context.

  • @opjakhar648
    @opjakhar648 3 роки тому

    Or upsc aisa koi qsn ni puchti vo b s&t m jo aa possible h Or 10 sal baad n ho

  • @khushijadaun9084
    @khushijadaun9084 3 роки тому

    Good evening sir

  • @Pragmatickk
    @Pragmatickk 3 роки тому

    Speed of light km me glt hai..sir g...3 lakh km per second hota hai

  • @shahidbhat751
    @shahidbhat751 3 роки тому

    Sir 38th question mein lid is part of body n is fixed. It cannot be the right option

  • @educationhub7069
    @educationhub7069 3 роки тому

    Sir 1st Question ke 2nd option me virus bhi likha h virus me plasmid nhi hota to usme recombinant DNA technology use nhi hoti

    • @wavee2496
      @wavee2496 3 роки тому

      Definately ...so my answer was a

    • @wavee2496
      @wavee2496 3 роки тому

      Pr sari coaching institute c bta rahi h

    • @souravkumarjha2876
      @souravkumarjha2876 2 роки тому

      Same yaar plasmid ko use kiya jata hai as a vector na ki bacteria ya virus ko. But sab coaching C answer de rue hai

  • @vinayakmohanjha7746
    @vinayakmohanjha7746 2 роки тому

    300 km per sec

  • @Uthkarsh7575
    @Uthkarsh7575 3 роки тому +5

    UPSC is gone made

    • @Uthkarsh7575
      @Uthkarsh7575 3 роки тому

      @@integrity2679 basically one who attempts less and gets most right with atleast 90 percent accuracy clears this exam even 60 qsns attempt with 7-8 mistakes would be good enough but can we do it is the question people want to attempt more but upsc pattern is changing

    • @Uthkarsh7575
      @Uthkarsh7575 3 роки тому

      @@integrity2679 s very true

    • @saketgautam7226
      @saketgautam7226 3 роки тому

      Upsc pattern is logic , inteligent guese not memorised stuff..

  • @swroopchand7897
    @swroopchand7897 3 роки тому

    Water is not dipolar 🙄...it have polar bond

  • @Nishantsinghrajputparmar
    @Nishantsinghrajputparmar 3 роки тому +1

    38 - (c)

  • @Neetmission-lv8gh
    @Neetmission-lv8gh 3 роки тому

    Hello sir

  • @JJ-bw5sn
    @JJ-bw5sn 3 роки тому

    Mere only 3 sahi hue 11 me se

  • @Travelshorts874
    @Travelshorts874 3 роки тому +1

    Sir Synthetic virology is a branch of science where man made virus are produced

    • @Eric..Cartman
      @Eric..Cartman 3 роки тому

      Virus are produced in labs. That's why China was blamed for manufacturing Coronavirus in Wuhan lab.

  • @opjakhar648
    @opjakhar648 3 роки тому

    So plz 🙏

  • @vipulpareek9073
    @vipulpareek9073 3 роки тому

    Jitne questions Modern History m sahi hoye the utne hi galat Science and tech m hogaya....

  • @opjakhar648
    @opjakhar648 3 роки тому

    Is baat ko smjho

  • @ajayr7346
    @ajayr7346 3 роки тому +7

    There are LED lights which are 360 degrees 😅

  • @rupanshi7317
    @rupanshi7317 3 роки тому

    Unidirectional h aur 360 degree m light produce kr rha h clear nhi hua...

  • @aman_870
    @aman_870 3 роки тому +1

    Respected sir, I filled test booklet code on OMR correctly but forgot to encircled the bubble on attendance code
    What will happen?

    • @someloner7082
      @someloner7082 3 роки тому

      That's not for us to fill. The supervisor will fill it up.

    • @aman_870
      @aman_870 3 роки тому

      @@someloner7082 than you sir for your cordial response but I think I couldn't explain my doubt clearly to you.
      Actually I am talking about that separate attendance OMR( other than OmR in which we mark our answers) in which our test booklet code( A orB orC..) was asked along with its serial no.

  • @opjakhar648
    @opjakhar648 3 роки тому

    Ye advanced technology h kuch b mr sakte h

  • @अन्तिमपद
    @अन्तिमपद 3 роки тому

    ua-cam.com/video/xOwLPAofrXk/v-deo.html upsc prelims answer key

  • @indivaragnivesh5407
    @indivaragnivesh5407 3 роки тому

    300 km/sec! kya bol rahe hain.

  • @vishwadeepupadhyay5458
    @vishwadeepupadhyay5458 3 роки тому

    Tume naa aa rho tou hoo btay rhu 38 kou answer d hoyego

  • @opjakhar648
    @opjakhar648 3 роки тому

    Bt merit 88 se upr ni rahegi

  • @RahulRajputAhmedabad
    @RahulRajputAhmedabad 3 роки тому

    😔😊😔

  • @opjakhar648
    @opjakhar648 3 роки тому +1

    Upsc ka only yhi targets h coaching ko khtm krna

    • @Hello-by7kg
      @Hello-by7kg 3 роки тому

      Desh me berozgari itni hai coaching jaege sab govt job

  • @asiffarhan5325
    @asiffarhan5325 3 роки тому

    Good evening sir