Strategy for Physics preparation by RISHAV GUPTA ,  IAS 

Standing on the shoulders of giants like Kashish Mittal (Civil Services AIR 58) , Amrit Singh Saini (IES AIR 1) and a few others, I started the preparation of Physics optional. I got a score of 266/500 in Physics ( 145/250 + 121/250). Here I would like to mention a few pitfalls and strategies regarding Physics that I realized during the preparation of this optional.

Taking Physics as an optional
My sincere request to every serious aspirant out there is to choose one’s optional carefully. Please do not blindly follow the rat race. Just because your friend is taking/ or has cleared with Public Administration or Geography or for that matter Physics, does not make that subject suitable for you. Every optional needs some interest and basic aptitude.
Give a cursory reading to a few optionals before deciding yours. I ,myself, gave a try to Political Science (10 days reading) , Sociology (did a Sociology course at IITD ) and Electrical Engineering (my Graduation subject) before settling for Physics and Geography in 2012 attempt and finally for Physics in 2013 attempt. Take Physics only if you like this subject and can solve its problems for hours without feeling bored.

I took coaching for Physics at DIAS, Jia Sarai, Delhi under the able guidance of Professor Vajpayee. He is a wonderful and passionate teacher. Only he can cover the whole Physics Syllabus within 4 months. Besides Physics, he taught us the art of answer writing, covering the syllabus ‘holistically’ and other finer points related to this peculiar exam. I also joined his Test Series. It proved helpful in improving my Physics answer-writing.
Books and Notes referred
• D.S. Mathur Click here
• J.C. Upadhyay
• DIAS notes
• Ajoy Ghatak View   Click 
• B.S. Aggarwal
• DIAS Notes
• Garg Bansal Ghosh
• DIAS Notes
• David J. Griffiths ( the best text book I have ever read )   Click here 
• DIAS Notes
Quantum Mechanics
• H.C. Verma
• DIAS Notes
Atomic and Molecular  
• DIAS Notes
• Rajkumar   Click here 
• Banwell
Nuclear Physics  Click here 
• DIAS Notes
• Brilliant Tutorial Notes
• Arthur Beiser
Solid State Physics
• Puri and Babbar   Click    Find here
One thing which is a must for scoring well in Physics optional is practice. I solved:
• Last 20 years IAS papers (DIAS Tutorial Sheets)
• Last 10 years IFS papers
• Behind the Chapter questions of all the books that I have mentioned above.
Notes There is a major difference in IIT – JEE and UPSC Exams. In the former, we do not need to memorize much, once we have understood the basics. But in the latter case, there should be no illusion regarding the fact that even in Physics, there is a lot of mugging up. You should have all the derivations on your finger tips. Some derivation in Paper 2 are more than 4 pages long. All the steps (substitutions, normalizations, calculus) in such derivations should be remembered by heart. In many cases, there is no alternative to rote memorization. Therefore, my serious advice to all the Physics guys preparing for Civil Services or IFS is to know your notes by heart. You should be able to derive the quantum states of a simple harmonic oscillator even in semi conscious state after waking up. I am not kidding. Its preferable to make you own notes. But in case you have not, you can refer to few of the notes available including those of Abhijeet Aggarwal, Supreet Singh Gulati or even my notes.

There is no use of covering a book if you cannot revise it in the last month before the exam. Believe me, there is a lot to cover in the last month. So the preferable thing to do is to make your notes in such a manner that in the end you need not cover anything else. So I will like to give three advises that might appear flimsy but trust me, they will prove extremely useful in the long run: • Always use a spiral binded notebook to make notes so that there is a option of adding in more pages afterwards.
• After each lecture leave 3-4 pages blank. In these pages, we can add important stuff from books including some theory or explanatory diagram or even some questions. (I almost copied the whole of Griffiths)
• Start a fresh lecture from Right Hand Side page. You will understand its importance once you start adding more pages in between.

Attempt Again this is not JEE where one get 100% marks for correct attempt. Even for a correct answer, UPSC awards 50% to 70% of the total marks allotted to a question, the variation is all about answer-writing. I attempted both the papers fully. But my correct attempt in Physics was ~230/250 in Paper 1 and ~240/250 in Paper 2. I got 145 and 121 respectively. So my advice is to attempt full paper ALWAYS. Even if you have some idea, answer it rationally and try to keep the attempt maximum. If your attempt is less, you are automatically out of the race.

Answer Writing
As I mentioned above, even for a correct answer, marks vary from 50% to 70%. The difference is Physics in the answer. A few additions that can make an answer better include: • Related Diagram
• A real life example of the concept in nature
• An actual application of the concept in today’s world
• Related Definitions and meta-data (discoverer, experiment that led to discovery etc.)

Last Day Revision 
As per the latest pattern, the number of holidays for Physics Exam have been reduced from 10 to 0. Therefore, it makes a lot of sense to make small summary sheets (5-6 pages) for each unit to revise in half an hour just before the exam day.
Best of Luck.