Tuesday 27 May 2014

It's "optics", can't you "see"

Optics is considered as one of the simplest portion in JEE syllabus.
Optics requires quite a bit of memorization and a good command over
basic high school mathematics (mainly geometry and algebra). One
should be comfortable with calculating unknown angles / distance etc.
The problems in optics are generally simple and easy to solve. But
there is an obstruction on the way – silly mistakes. Since the
questions are mainly mathematical, it’s very easy to make silly
mistakes. So, it is advisable to practice plenty of questions from
optics.
Also, there are quite a bit of formulas involved in geometrical optics
part (u-v formula for lenses/mirrors, laws of reflection and
refraction, etc). So, it’s better to understand the derivations as
well which will surely help in tough situations.
Keep in mind that optics portion has a huge weightage in JEE and so, a
candidate aspiring for a good rank cannot afford to give away marks so
easily.
As usual, we will go chapter wise (as mentioned in JEE syllabus):


•       Rectilinear propagation of light: This portion mainly includes the
elementary properties of light. The basic properties about the nature
of light coupled with laws of reflection and refraction form the basic
framework of the entire optics. So, students should understand these
topics very well and practice ample of questions. Simple ideas can be
effectively used to frame complicated questions but those who have a
good understanding of basic concepts won’t face any problems.
The ideas of total internal reflection and deviation of light by a
prism are simple but slightly theoretical. So, one must read enough
theory for these concepts. Good questions are asked from total
internal reflection and the questions asked are generally “new” ones.


•       Reflection and refraction at plane and spherical surface: The ideas
covered in the last chapter will be improved and the concepts of
reflection and refraction at curved surface will be introduced. As
before, the ideas taught in this chapter will be used in the next
chapter. You will be taught a couple of equations which will be used
to predict the path of reflected/refracted ray. There will be a few
derivations involved which are simple yet important and must be
understood very well.


•       Spherical mirrors: The idea of reflection of light will be improved
upon to develop the idea of reflection of light from spherical
mirrors. A new equation called the u-v equation for mirrors will be
introduced. There will be several cases of position of objects and
associated images. Students must keep in mind the properties of images
formed for a given position of object. The idea of lateral
magnification helps a lot to predict the size of image. Proper care of
sign convention must be taken to avoid silly mistake.


•       Lenses: The idea of refraction of light at a curved surface will be
used to build up the concept of lenses. A new equation called the u-v
equation for lenses will be introduced in this chapter. Note that the
u-v equation for lenses is quite similar to the u-v equation for
mirrors. So, students should ensure that they do not interchange the 2
equations while solving problems. It’s very easy to make silly
mistakes here and it has been seen that even very vigilante students
make mistake here. One must take care of appropriate sign convention
while solving questions of lenses. Mind bending questions are also
asked from combination of lenses. One must keep the idea of “power of
a lens” in mind while solving problems of combination of lenses. The
idea of “effective focal length” helps a lot in solving problems
involving lenses separated by a distance.


•       Combination of lenses and mirrors: Most questions of optics are
asked from this portion. If the student is weak in any of above
topics, he/she is likely to face problems in solving JEE questions. So
to solve (apparently) complicated questions, students should focus on
the basic ideas taught in the previous chapters and integrate them in
the correct way.


•       Wave optics: “Huygen’s principles” form the basics of this chapter.
The idea of wavefront is the basic idea and must be understood very
well. Students tend to ignore this portion and the JEE paper setters
are pretty much aware of this so they have started asking very good
“paragraph” type questions from this portion. So, avoiding this part
may significantly affect your rank.
Next comes the famous YDSE – Young’s double slit experiment – a very
important idea. Every year there is at least 1 question from YDSE.
Very frequently questions on “modified YDSE” are also asked. For
example – a glass slab is introduced in front of 1 or both slits. The
key to solve this problem is the idea of “phase and path difference”.
Students are advised to practice variety of questions from YDSE
portion.

To summarize, optics covers a variety of simple ideas which are very
common in JEE. So, students aiming for a seat should not ignore the
optics portion. Solving as many problems as possible will surely help
you to get a firm command over optics portion.


Recommended textbooks: HC Verma, DC Pandey, NCERT, Resnick Halliday 

Monday 26 May 2014

Electromagnetism: Electrify yourself!

Electromagnetism forms the major part of the class 12th syllabus and is one of the highly weighted sections for JEE Physics. This entire module requires a lot of practice, intuition and problem solving skills. The mechanics portion learnt in class 11th acts as tool to solve the problems of electromagnetism (Yes! You are going to need it!  Quite a lot from sections: energy conservation, momentum conservation and Newton’s laws of motion).
Let’s go chapter wise to make things simpler:

Electrostatics: Electrostatics begins with Coulomb’s law, principle of superposition and then goes on to the concept of electric field, electrostatic potential and other ideas that form the basis of electromagnetism. These are the fundamental concepts and the students are advised to get a thorough understanding of these topics. Sufficient practice is required for all of these topics. In JEE, simple questions are asked from this topic which can be cracked easily, if one has refined concepts. An important portion of electrostatics is the concept of “conductors in electrostatics”. Most questions in electrostatics are based on the properties of conductors under electrostatic condition. So, it is recommended that students should practice ample of questions from this topic. Another extremely important idea is the idea of electrostatic flux and Gauss’s law. Both of these ideas are highly important and if one can correlate them with other topics, they can be very useful to solve completely unrelated problems. Usually, there is always a question in JEE which ultimately involves calculation of flux of a charge through some or the other surface.

Capacitors: This chapter is another simple but important part of JEE syllabus. It is basically the application part of electrostatics. Those who have covered electrostatics well would find this chapter a cakewalk. Some new concepts taught in this chapter are very interesting and easy to understand. This chapter is important from the point of view of Olympiads as well. The idea of dielectrics is also introduced with this chapter and a number of questions are asked in JEE which require you to calculate energy stored in capacitor / electric field by capacitor, etc. – all involving concept of dielectrics. In fact, an entire question in INPhO 2013 was based on a capacitor with a dielectric whose dielectric constant varied as a function of position.

Current electricity: Ohm’s law and Kirchoff’s law form the key framework of this chapter. It’s one of the easiest chapters in JEE syllabus and it takes only a little effort to master it. However, the chapter has fairly good weightage in JEE and so it is recommended that students practice a large number of questions from this chapter so as to avoid silly mistakes in the exam. RC circuits are very important from the point of JEE. One should keep the “mechanical analogy” in mind while solving the problems of RC circuits. Sometimes, a tough RC circuit problem can be solved within a minute if one is able to figure the appropriate mechanical analogy. Another important concept is “heating effect of electric current”. This concept combined with the ideas of thermodynamics may be used to form some of the best mind bending questions.

Magnetism: This chapter involves numerous applications of the mechanics portion learnt in class 11th. Good questions are framed under the concept of a particle in an electric as well as magnetic field. And one should be thorough with various concepts of mechanics to be able to solve the problems, particularly, basic kinematics, work energy theorem (+ the idea that magnetic field doesn’t do any work), law of conservation of linear momentum, etc. Most questions are asked from calculation of magnetic field in various cases. Another important “centre” of questions is – Magnetic moment. It has been observed that there are a few questions in JEE from magnetic moment, every year. So, it is recommended that students practice enough questions involving calculation of magnetic moment and related applications like – basic idea of magnetic materials and the explanation using the concept of magnetic moment. A loop in a uniform magnetic field is also an important topic of discussion. Several questions are asked from this. Some good problems are also derived from the concept of “moving coil galvanometer”. So, boot yourselves up and get ready to see a few new questions in JEE from magnetism as well. 

To conclude, Electromagnetism forms a big portion of JEE syllabus and if practiced properly, it may help you change your rank completely. But, at the same time, Electromagnetism needs a lot of practice and patience to master. Initially, one may find it boring/ difficult to understand for whatever reasons, but it becomes very easy (and fun too!) if ample no. of questions are practiced from the prescribed textbooks/ study material.
Recommended books: DC Pandey, HC Verma, NCERT, Resnick Halliday

Tuesday 6 May 2014

Mental preparation for JEE Advanced

Around 20 days are left for the exam you have been waiting for since the past few years. I assume that your syllabus has been completed by now.
This post will focus on "the" day. How to mentally prepare yourself for the exam. I will try my best to expose to you every inch of my final day so that you can get an idea of how it goes.
Firstly I will be describing my thoughts during the last month.
Then I will be talking about "the" day

The last month was a bit rigorous. JEE was on the head and the sun as well. Scorching heat. Can't imagine a life without an air conditioner. But wait!!
"You won't get an AC in the examination hall" - I said to myself.
So, I remained in my room with AC switched off. I always tried to keep the AC off so that I don't face problems on the final day.
Next - my study methodology during this month.
I mainly focussed on past year JEE problems. I was enrolled in FIITJEE AITS but I stopped giving it during this month. It is extremely hot outside and it's better to stay at home and do some self study. The test centre was more than 10 kms away from my home so I preferred not to go there. I stayed at home and practised a lot.
For chemistry, I did the complete FIITJEE archive once again.
For those who don't know what an archive is - It's a collection of past year JEE problems from 1980 onwards. You can purchase it from the market if you don't have one. It's extremely important to give at least 1 try to the past year JEE problems. I assume that you are not in the crowd. You are a bit ahead of the crowd.
For maths and physics , I focused on subjective problems of the past years. The idea was to solve the subjective problems and try to frame objective questions from it - this is what they will do in JEE as well.

My study hours were increased to as high as 14 hours a day!
It's tough to maintain that. But there was a driving force - A hunger to study in the top college of India - A greed to "choose the branch" and not "be chosen by the branch".
Just think it yourself - A month more ; rather less than a month more to go. Why not be a true warrior ? Don't accept defeat. Fight till the end. JEE main marks have come now.
If you have got less marks - accept it as it is, and try to do better in JEE advanced.
If you have got good marks - take it as an achievement and try to do well in JEE advanced as well.

Mental scenario : The fear , the anxiety , the nervousness , excitement. I also had to bear all that. Same thoughts went onto my mind - 
what if maths section is tough ? 
What if I make a bubbling error ? 
What if I go completely blank ?
What if I am not able to do well ?

Well I had one plus point - A huge plus point indeed. I was discussing it with my friend yesterday ;) . My parents never bounded expectations from me. They never "hoped" anything. They always motivated me - told me not to take any pressure. They never expected a 2 digit rank from me. Never told me - "we expect a lot from you" or any other thing like that. And that was very important for me. I didn't have any burden on me.
Father always said - "don't take any load on yourself. Your father's business is always open for you."
This way , JEE preparation was fun for me. I enjoyed it.
Just stay focused and motivated.

Now, I will be talking about "the" day

June 2 , 2013 was the day for me.
June 1 , 2013 - it was a beautiful day. It rained slightly and we all were happy that the weather is not that hot.
By evening, I had packed my bag with all the relevant documents , pens , etc.
Next, I went to sleep at my usual time - 10.00 PM
I felt restless.
Couldn't sleep at all.
Something scared me - something was going in my mind - something that didn't let me sleep at all.
I became worried - "what if I am not able to sleep now and what if I feel sleepy tomorrow during the exam ? "
I Explained the situation to my mother who was still awake.
She told me to mentally read "Hanumaan Chalisa" and told me that I will fall asleep if I read it.
I tried it but still couldn't sleep.
Meanwhile I realized that it's 12 and I am still awake.
Finally don't know how, but I fell asleep.
At around 1 o'clock, the phone rang - I was extremely irritated. It was my uncle who wanted to wish me best of luck for the next day. I was frustrated a lot - "why on the earth did he call me NOW. Didn't he get any other time ?". Anyway , I talked to him - ended the call - murmured something to my mom (I was angry because she didn't put her phone on silent mode).
Finally I had fallen asleep.
Next day I woke up at 6.30 or something (I don't remember exact time).
It was a horribly hot day - sun shining brightly right on the head.
It was so hot - I was sweating already.
We were worried because today was "the day".
I got ready within half an hour or so. Left home at 7.15 with my father (Keeping some time extra in case car breaks down or something unexpected happens).
Reached within 30 minutes to the centre because it was a Sunday morning and there was almost no traffic.
I was practically the first student to reach there (there were a few although).
It was so hot - I was sweating. Father gave me his handkerchief as well (besides my own).
Finally after a lot of wait , it was time to enter the examination hall.
Went inside.
Prayed to God to make the things go well.
I remembered all my past achievements - in order to gather strength - the mental strength to boost my confidence.
I was a bit scared by now.

But then I thought (I am putting the exact words) - "You have worked hard - extremely hard. You cracked those olympiads. If you are scared today , then who the hell isn't scared. Come on man - you have fared well in the toughest of the FIITJEE's tests - you can do it. Do it for your mother and father - make them proud man - come on."

Yes!! these were the exact words (in maybe a jumbled order) - I still remember them.
Speaking all these to myself gave me a lot of confidence - A LOT OF CONFIDENCE indeed.
Meanwhile the invigilators started distributing the papers. We were instructed not to break the seal of the paper until instructed to do so.
I completed the OMR (personal details). 
Realized that it was a 180 mark paper with negative marking everywhere - that scared the hell out of me !!
"MORE THAN ONE CORRECT QUESTIONS WITH NEGATIVE MARKING"!! - What the hell is this!!
Any ways - Started with physics - Did quite well - couldn't do 1 integer type question because it needed some sort of series expansion and I couldn't figure it at that instance.
Physics went well.
I had left a few questions though.
Moved on to chemistry - "TOUGH", I said to myself - it was indeed very tough for me - all theoretical questions with negative marking everywhere - it was difficult to do.
Anyway, it went on
I was sweating like anything
I had 2 handkerchiefs.
By now both were soaked with sweat.
I realized that maybe OMR gets damaged if sweat falls on it.
So, I safely kept it in the desk provided.
Paper went on. After some 1.30 hours, physics and chemistry were over.
Time for maths - "WHAT IS THIS ??" - it was very tough for me - I wasn't that strong a maths - Paper seemed to be slipping from my hands.
Any way - the painful 3 hours ended.
I came out
soaked in sweat with 2 wet handkerchiefs - maybe stinking (Yes - I literally seemed to be in a beggar like state).
The paper banged me - heavily
My face was down.
Then I saw my father.
Seeing my face my mother said - "Was the paper bad ? Will you get IIT Kanpur CS at least ?"
I said nothing - didn't have words to explain.
My parents then realized that I have screwed the paper - screwed it badly.
I was taken to the car.
My mother gave me cold water - poured some drops of gulabjal into my eyes.
She sat on the back seat of the car and I lied on her lap - disheartened.

Then my father came to me - "Son. Listen. I know the paper was tough. I can read it on your face. But do remember that the paper was tough not only for you - but for everyone - if you cannot do it , no one would be able to do it. Your score might go down but your aim of an under 100 rank will go nowhere. So relax. You are a TOPPER my son."

Those words gave me immense strength. I realized the importance of his words. Each and every word was indeed true.
I haven't screwed the paper. It was tough but I didn't screw it - everyone must have done badly. So, I kept calm.
Meanwhile mother took out the tiffin and gave me my lunch.
Then, she gave me some fruits.
I felt relaxed. We got some cold drinks and finally I was back in the race.
I realized that I should keep calm. I should not do the same in the second paper. I should not lose my calm at any cost.
Finally, I entered the hall once again for paper 2.
Again attempted in the same order but this time a bit more careful.
Again the negative marking in the multiple correct questions bowled me completely.
Physics and chemistry were over.
Came to maths.
Clean bowled.
Made 1 bubbling error as well.
Chemistry was tough - now maths again!!!
Scared I was completely.
Next comes the interesting part
2 minutes left
Stuck on a paragraph in maths
Bell rang
Paper collection begins
High pressure and heat
Fortunately I was sitting in the corner seat and it took time for the examiners to collect my paper.
In those 2-3 minutes, I managed to get that paragraph - "CORRECTLY"
Well , this way ended a journey of 2 years.
Paper 2 went way better than paper 1.
Although I was disheartened a bit.
Came out - met my father.
Finally went back home.
I realized that my rank may go beyond 500 - Trust me I never thought that I would end up with what I got.
Then when I reached home , my sister was present at home.
I was sad - my parents and sister cheered me up.
Finally I got a call from my friend Kartikeya asking me how I did.
Then my sir called me up and asked how the paper was.
I mailed him the photograph of the copy of my OMR sheet.
I explained him that the paper went bad.
Extremely sad and depressed - But finally it was over so I was relieved a lot.
I remember I didn't eat anything that evening - "I was crying - literally crying alone" - "What have you done ? You have completely spoilt the paper. Forget your dream. Forget IIT Bombay - forget CS".
Believe me - there were tears in my eyes at that time. Yes I was crying!!
Somehow ate something and slept.
My parents didn't say anything to me - I told them to leave me alone and they know that when I am sad, I need some time with myself - Only myself.
Got up next day. By that time, my sir had checked my answers and also got reports of how other students performed. I was still asleep.
Woke up - saw that my father is extremely happy - I was shocked!!
He told me - "Manoj sir called us. He is saying that you have done very well with respect to others. Under 50 rank is sure under any circumstances". 
I didn't believe him - he must be saying that to make me cheerful.
Then I called my sir - He told me all the statistics which he had gathered.
Aaahhhh - sigh of relief. He told me that my score would be in the range 290 - 300.
I didn't expect a good rank with that score but then he went on - "I got reports of very few (fiitjee) students who are scoring that much. You have done very well. So keep calm".
That statement made me feel happy - I felt relieved. I talked to my friends and found that indeed I had performed very well with respect to others.
Any ways - It was all over and I was convinced that I am in the top 50s for sure.
Played
Enjoyed
And cherished the moments when the result came
IIT JEE is a beautiful journey - a journey that will leave a mark in your life - an awesome journey that will teach you a lot - patience , motivation , confidence , perseverance , accepting defeat , fighting spirit and many more good qualities that will help you throughout your life.
You won't experience another such journey in your life.
Enjoy it now.
All the best.
That was my story.
Feel free to post all kinds of doubts