Problem Solving Strategies

But real lenses aren't perfect, and real light isn't perfectly parallel, so although most of the light does form a single spot you get some light forming more complicated patterns.

Wolgwang

John Rennie

I don't think there is a simple way to explain the complicated patterns around the spot.

Wolgwang

@JohnRennie So I have to measure the length between the screen and the lens when the spot is brightest to get focal length?

John Rennie

If the light entering the lens is parallel then the spot is formed a distance f away from the lens.

That isn't a very accurate way to measure f though as it's hard to get exactly parallel light.

A better way is to put the lens on a mirror and look for the point where the object and image coincide.

Wolgwang

7:08 AM

@JohnRennie Uhm?

Can you draw a diagram?

John Rennie

I was just Googling to look or articles on it.

There is a Word document describing the experiment here

Wolgwang

Thanks :-)

Buraian

2:33 PM

The JEE preparation has no value, you end up learning a lot of formulas without having no explanation for it.

Learning is good, but that exam asks a very specific kind of studying to clear it. You won't get far if you try to understand each thing , you have to like take a large amount of things as a given and learn algorithims to solve problems basically which I see no value of.

And actually what mr. rennie said has some truth because if you look at placement stats, after the undergrad or something only 90% of people placed in IITs , so we can guess how it will be in worse colleges. There…

satan 29

2:46 PM

@Buraian Ill disagree with the first part actually, thats the epitome of not being prepared at all as far as jeeA is concerned

Buraian

Well perhaps for advanced it is different but the reality is your JEE main score is weighted for your final score ( I think?) and further to get to write advanced itself you have to clear JEE mains

satan 29

its not weighted

you just need to clear it

Buraian

Oh

As per advanced, I think the exam is totally in calibrated in the sense that it doesn't even know the portion which the student should know . For example in 2016 there was this question of this double disc rotating about a rod. Now, a person who hasn't done a book like kleppner / done vector nature of angular momentum would never be able to answer that

but if you can already do questions like that then why do you even need to get into a college lol coz that portion is same thing they cover in first year

satan 29

i mean there are a lot of things about jee that are worth criticism , but as far as 'learning" is concerned, it needs to praised

Buraian

And also, I think it is more about knowing what to apply were and what are the rules of each thing rather than understanding "Ok why is this thing"

well the problem is it hasn't made any competent engineers in our coutnry

satan 29

2:51 PM

@Buraian again, this does not work at all for advanced

@Buraian point taken

Buraian

Advanced requires you to know where to ues what and what does what rather than why does what

satan 29

but just from an academic exam POV, its definitely highly, HIGHLY conceptual.

Buraian

well yes if you remove that it is an Engineering exam and all that packaging stuff, there are definitely some great questions in it

satan 29

@Buraian not at all actually, people with that kind of prep dont do very well

Buraian

Eh, I've seen enough people to say that is not the case

satan 29

2:54 PM

roughly 60% of the advanced exam questions requires absolutely in depth knowledge of whats happening, i will vouch for that

all of your points are valid for mains though.

Buraian

Hm, I'm not sure how much I agree yet but I will do a much more detailed study/ write up on it in the future

there are some high level theory questions in advanced, no doubt about it

satan 29

well in 2020, some--->most

Buraian

Hmm will solve that paper soon enough :P

satan 29

wrong group, oops

Snapdragon-X

3:08 PM

@Buraian The unplaced 10% do not constitute the taxi driver standards. Secondly, the majority of the 20% I mentioned end up getting a middle-upper class life in India. You won't get far if you try to understand each thing... you possibly meant that there's too much to study but no, that's not the case. I did advanced mechanics while prep. (Lagrangian, Hamiltonian) and it was pretty useful in some chapters (even helped in Calc.). (1/n)

Buraian

kek

as a person who has yet to write JEE and done a lot of higher math

I can say it is mostly useless

lagrangian is completely useless if you have friction, only for very very very small subset of problems

in jee level at least

hamiltonian.. uh not so sure how much more useful it is than lagrangian

Snapdragon-X

@Buraian 0 except I just learned stuff like legendre

@Buraian and how

The college first years in most parts of the country teach these

Buraian

ye

Snapdragon-X

L.A. Calc 3 etc.etc.

Buraian

I just learned from youtube

I have pretty much documented everything through asking questions on stack LOL

Snapdragon-X

3:11 PM

@Buraian documented what?

Buraian

as in, my studying

Snapdragon-X

Oh when are you giving JEEm 2022?

Buraian

cause I put all my questions here, I didn't go to coaching or anything and my school was pretty bad

I'm givin it this year

Snapdragon-X

@Buraian great...all the best for the upcoming 3 shifts

@Buraian coaching is actually ....umm depends on the person

Buraian

it's the 'standard'

as jee is the 'standard' exam , coaching is the 'standard' way. Good thing most people are realising it is useless nowadays

Snapdragon-X

3:13 PM

A guy Aniruddha Deb (he's on chemistry stackexchange and here as well). He didn't go to any specific coaching and managed to get AIR 300 something

@Buraian yeah it is actually...and I am NOT guilty for being a part...though it's a semi scam....a lot of learning involved

Buraian

as much as I respect the people who scored well and did hard work for the exam, the exam in it self is an ill posed challenge to highschoolers

Snapdragon-X

@Buraian True

but as Thanos said.... Too many mouths, not many places to move about

Buraian

The way that is said is the most insulting thing I ever hear

Snapdragon-X

what

Buraian

Like we are screwing over our people to support a garbage system which produces not much result for teh amount of sacrifices put into it

it really makes you wonder what is the value of a single Indian highschoolers life

almost nothing because engineering is that over saturated

Snapdragon-X

3:16 PM

yeah...engineering doctor and mass communication (media)

Buraian

actually I think neet is better than engineering for a person looking for the job security these days, the doctor job is less saturated than engineers afaik. Overall I have a very negative view point on all these matters, I sure do hope the government starts making reforms. One of my biggest happinesses of last year was the new education policy which got implemented

Snapdragon-X

idk but it seems to be a blessing to have joined a platform like S.E. else I would have burned away my skills

Buraian

true

the good will of people on SE is what contributed to the little I know

Snapdragon-X

@Buraian NEP allows fluidity...but security?

Buraian

also the free lectures by the top unis like MIT and all. God bless them

I mean the thing is there was no security before itself

Snapdragon-X

3:18 PM

@Buraian Yes...Also bless NPTEL lol

Buraian

collegedekho.com/news/….

this is the top result of the previous system

Snapdragon-X

@Buraian there was atleast a set path....now colleges will have tough time selecting students given that they reform their exams fitting the NEP

Buraian

I am happy for it

Snapdragon-X

I am more of neutral

Buraian

Hmm I'm certain that it is a much better change but the real problem is getting teachers to implement

Snapdragon-X

3:20 PM

Agree

Buraian

sorry that I went off on about JEE a few minutes ago, I just have strong feelings for this exam haha. It was nice meeting you, where you from btw?

Snapdragon-X

@Buraian The same place where JEE belongs to ;0 been there done that...now in first year at IIITD CSE

Buraian

wdym by same place where JEE belongs too

thonk

Snapdragon-X

@Buraian India?

Buraian

@Snapdragon-X

oh bruh

I am Indian too

though I live in kuwait now

Snapdragon-X

3:24 PM

xD

@Buraian Oh I saw you wrote kerala in your profile so I assumed Indian

Buraian

ye I am Indian only, I studied in cbse till last year

I want to write JEE but covid blocked flights

Snapdragon-X

@Buraian Nice so you've permanantly shifted?

Buraian

this year we got a center in kuwait, so most likely gonna write it here itself

Snapdragon-X

@Buraian Oh....so you couldnt give JEE....that's sad

Buraian

naw

I am honestly glad I didn't write lol

Snapdragon-X

3:26 PM

@Buraian Intl. center woaah

Buraian

I knew less than quarter of stuff last year , I had about five months where I could just randomly go about and read whatever I wanted

it was pretty great, however quarantine lead to breaking off ties with friends and killing my social life lol

ye

Snapdragon-X

@Buraian There was a big stupidity done by NTA...they accepted only integers but allowed a user to fill decimal places...the instrucuctions weren't clear enough

Buraian

BrUH

Snapdragon-X

Even the inorganic section outweighed and extinguished physical section commpletely in Shift2 Feb26

@Buraian idk but I built stronger ties with some people LOL

Buraian

I wanted to forget that inorganic existed

damn covid friendships

Snapdragon-X

3:28 PM

@Buraian Inorganic is actually interesting ....apart from s,p,d,f, blocks

Buraian