Tuesday, August 26, 2008

Physics - Mains (Part IV)

Electricity and Magnetism: I had studied Field and Wave Electromagnetics by D K Cheng at college and that remained my textbook for the topic. It explains concepts well but it is not a popular book though and neither is it sufficient.

Cheng does not cover multipole expansion which is done adequately in Griffiths (a popular textbook for the topic). Cheng is quite good in solutions to boundary value problems. Magnetic shell is from D C Tayal. Clausius Mossoti equation can be done from textbook in Solid State Physics.

Cheng and Tayal are ok for Current Electricity portion of the syllabus.

Chopra/Aggarwal is a must for Electromagnetic waves. It’s a good book. Concepts are explained well in Cheng also but not in sufficient detail. EM Field Tensor and covariance are from J C Upadhyaya (Classical Mechanics). Rayleigh scattering is dealt well in Chopra/Aggarwal.

For Black Body Radiation and Thermal and Stastical Physics two books are needed – Thermal Physics by Garg/Bansal/Ghosh and Heat Thermodynamics and Statistical Physics by Satya Prakash. Garg/Bansal/Ghosh is a better book for most topics. So be thorough with it.

Satya Prakash is needed mostly for Otto and Diesel Engines, derivations of statistical distributions (Maxwell-Boltzmann, Fermi-Dirac, Bose-Einstein). Again stick to the syllabus and prepare answers. There will be more than one way to derive many questions. Be thorough with the one you are confident about.


Atirek said...

Hi Supreet,

First of all thanks for such elaborate guidance on attempting Physics Paper. I am a working Professional (South India) and wrote Mains in 2008 with Physics and Maths. However i realized my mistake after getting some real bad marks in Maths (which ultimately led to me not qualifying for Inetrviews). This time i chosen PubAd as an optional. However i am relying heavily on Physics for good marks, partly coz i don't get enough time to study so elaborately for GS and PubAd and partly coz i have done Msc Physics from JNU so have a background in it.

I have some doubts regarding writing answers in Physics which i am listing down:

1) What makes the difference between someone who gets 400 marks in Physics and someone who gets 280-300. I mean what should be the approach for writing answers, specially considering the lengthy paper and limited time limit.

2) Is it that markings are also done Unitwise e.g. attempting quetsions from certain units e.g. Electricity and Magnetism may fetch u good marks than those from Mechanics or so.

3) Is it that, Attempting Numerical Question is more beneficial than attempting theoretical ones (e.g. Notes on Hard/soft Superconductors)

4) Even for derivations is it important to start from scratch or one can start from a point and skip some detailed calculations(especially derivations in Q.M.).

5) Also in case of derivations and Problem solving is it necessary to give explanations for the steps taken or principles involved, or can they be left considering the huge time strain.

I will be really grateful for ur time to answer these queries as i dont have anyone else for guidance and suggestion.


Supreet Singh Gulati said...

Hi Atirek,

First, well written theoretical answers fetch MORE marks than numericals in this exam. That's a fact.

Secondly, Please don't think one unit is more scoring than other. Just write good answers on topics you know well.

Thirdly, mentioning principles and concepts from scratch is a must. Please don't remove that from your answers. You may remove Maths if you are short of time but please, still explain the concepts. In Q.M. the only place where I thought I'll leave out Maths was in Hydrogen Atom (I decided I won't convert two body problem into one body mathematically, but just explain center of mass concept and start off as a one body problem explaining significance of each term in the equation). It will take lots of practice to get the answers correct in time. Give yourself those hours during preparation (don't just read over and over again, keep writing answers day in and day out esp. now that you have taken Mains once and are probably well conversed with basics).

I am sending links to my solutions (CSE 2007) in a new post. Please go through them. That will help you to write a good answer in Physics.

All the best

Supreet Singh

Radha Krishna said...

hi supreet,
can you please provide the title of Chopra/Aggarwal for electromagnetics.

uday said...

Hello Supreet ji,
Could u plz mention the name of author and book in detail, because an author generally writes many book. Plz mention book and author name in detail for thermodynamics, black body radiation and quantum mechanics I and II. You can also mention for nuclear physics, particle physics, solid state physics and electronics.
One more thing, I really have a doubt over whether carrying two science subjects viz. phy+ che is very hard? Though as u said earlier about science students having weak writing skill, it is true. I am in IITk and whenever I start writing on some humanity subjects, I fall short of words. That is why I want to avoid connection with humanity subjects. Any way, I wish to know ur experience abt u carrying two science subjects together. was it really hard to cope up with both?

This comment has been removed by the author.

hello supreet sir.....
sir currently i'm in my b.tech(instrumentation engg) 3rd(6th sem) yr,. I want to start the preparation.sir, i'hv some doubt regarding choosing the optionals.sir, instrum. syllabus matches upto 90 perc with the ee.
But physics was my favourite subject during +2 and even now i hv interest in this subject.
sir, i want to know which one is more easy to handle physics or electrical.
My 2nd optional is geography.sir, should i take geography in my prelims or one of the two mentioned science subjects
I will be really grateful to you if you find some time to answer these queries


sanjay said...

kindly help me out for bird watching hobby, ur suggestions wud have immence value for me