CSE Physics Optional Strategy

First of all I must thanks the giant of UPSC Physics preparation – D P Vajpayee sir. He has made it possible that I am writing this blog today. I took coaching for Physics from DIAS in 2014 and appeared for test series in 2016.

Secondly, my sincere gratitude to previous years toppers – Supreet Singh Gulati Sir (2007), Abhijeet Agarwal Sir (2009), Kashish Mittal Sir (2012), Divyanshu Jha Sir (2013), Manish Bansal Sir (2013), Rishav Gupta Sir (2013), Vishu Mahajan (2016) and Prateek Jain (2016). I have immensely benefited from their strategy, notes and guidance in past 4 years.

Book list – I stuck to just one book for each topic except for Paper 2 where Resnick and Eisberg helps in covering some topics in Modern Physics.
  • Mechanics
    • JCUpadhyay
  • Optics
    • Ghatak
  • Electricity and magentism
    • Griffith and SP
  • Thermo
    • Garg, bansal, ghosh
  • Resnick and Eisberg
  • Quantum
    • HCV
  • Atomic and molecular
    • Rajkumar and ban well
  • Nuclear and Particle
    • SBPatel
  • Solid state and digital electronics
    • Puri and babbart

Other sources

  • I came across Hyperphysics very late in my preparation. It is immensely helpful for notes making as well to understand certain concepts. You will find a whole of easy to draw diagrams on this.
  • Abhijeet Sir’s notes – available on his blog cited above – use it for in depth study only if you have time.
  • Rishav Sir’s notes – available on his blog cited above – They should be your primary source. He has covered almost all the topics succinctly
  • Brilliant Tutorial Notes – They are usually available in photocopy form in ORN or Ber Sarai market. They are beneficial to cover previous year questions. Also topics like Solid state and digital electronics can be covered from them
  • DIAS classroom notes – If you are not able to attend the classes then get the latest notes from one of the students attending them. All your other notes would be structured around them.

Test series at DIAS

  • You must write all the test. And on time
  • Many opt for test series by correspondence. I would advice against that. There is no way you can simulate that environment sitting 2000km away. The experience of giving the test series at the centre is very different

Answer writing – This is a highly important part in preparation. You need to practice this well. You can get 50-70% marks for a correct answer (taking into account scaling etc)

  • Best way is to prepare model answers for all your tutorial sheets. Get model UPSC answer booklets from market and start writing answers for previous year questions from tutorial sheets. Tutorial Sheet, Previous Year Papers
  • Make it a habit to add a line or two in the beginning and end of the answer. This could be related to the physics/definition of the concept asked in the question or a comment on the answer (like for HUP – you can write that such value of answer make it improbable to witness it directly). You can also write real world application for the concept asked or some meta data like who is the discoverer or which experiment led to the discovery of the concept
  • Draw diagrams as far as possible.
  • Use a different coloured pen (black if you are using blue for writing) for diagrams and underlining
  • Be very neat in your presentation. Reduce the cutting
  • Most critically, choose the questions carefully. Prepare at least 3 topics out of 4 in each paper thoroughly so that you can attempt 90% paper.
  • You can have a look at these model answers by Supreet Sir – Model Answers by Supreet Sir

Notes making – You should ideally take notes in Vajpayee sir class on one side of A4 sheets. Leave the other side blank to add further notes from books or other sources

Revision – Prepare revision notes (summary sheets – 3-4 pages for each units). Cant emphasize the importance of this. If you don’t have these, you’ll be overwhelmed just before the exam by the sheer size of the notes. Have a look at Prateek Jain blog for these flash notes.

I got 303/500 last year and 327/500 this year. On the other hand my preparation last year was much better than this year. But you never know what works in your favour.

All the best!





Optional Selection

I think this is one area which gets least attention from many aspirants.

Usually a new candidate goes by the conventional wisdom of those whom he know personally. But one should also do one’s own research before choosing optional. They should look at study material of different optionals, listen to what previous year toppers are saying, read blogs, speak to teachers before deciding the optionals.

The following factors are usually considered while choosing a optional

  • Less syllabus so that it can be covered fast
  • Same subject as taken by a friends
  • Perception of being “easy”
  • Overlap with GS

Among this many forget the most critical factor that should be game changer in deciding optional is how scoring the subject is. An optional is one area where you can confidently score good marks. Because in GS it is very difficult to improve from 100 to 110 but it is possible to improve from 250 to 300 in an optional if chose wisely.

Keeping these in mind I am a strong advocate of science and engineering optional. Once they are done thoroughly you can be assured of 280+ score . This is not so with many humanities optional. Also I heard from many aspirants that they are stuck at a particular score in  mains in even after 3 attempts. And this becomes critical for their selection because it is the mains score which will take you the final list. Many just miss out from a rank because their mains marks are just not there. And optional is the main culprit here.

Thus an aspirant need to honestly think about pros and cons of choosing a optional. Yes, science and engineering subject demands a certain aptitude, inclination and interest but many just shy away from science optional because they demand hard work and take long time to prepare.

When I chose my optional, I had option of Geography, Anthropology and of course PubAd. But I went with Physics. Physics wasn’t my forte but I had a interest in it. I always wanted to study it but couldn’t during college years due to various reasons. I knew that Physics will bring diversity to my preparation as this is not a matter of 1 or 2 year because I might have to spend more time in preparation. It will help me in breaking the monotonicity of GS .Moreover it was a highly scoring subject. Many of may seniors of college (Manish Bansal Sir, Rishav Gupta Sir) had cleared the exam with this optional. So I chose Physics.

Choice is yours. Be wise!

PS – This post is based on personal experience and not any kind of data.


IFoS – Forestry optional

My score – 254/400
There are two papers of 200 marks each. It is possible to score unto 65% in this optional (as per this year marking)
Book list and resources


  •  I went through entire syllabus before prelims once. This helped me in saving precious time between Prelims and Mains as CSE mains was also lined up after IFoS’s
  • I made few shorts notes for revision especially
  • I solved the questions that are given at the end of each chapter in the book. Wikipedia and internet research helped
  • Draw as many diagram as possible – colour them if you can
  • Don’t take it lightly because it has same marks as other optional as well as more marks than GK

IFoS – Physics optional

My score – 278/400
I joined DIAS for Physics classes and their test series. More than anything else, the motivation by Vajpayee Sir played an important role in me getting good marks in Physics.
To do
  • Solve all DIAS tutorials properly in UPSC like notebook – Gives you a feel of space, presentation etc
  • Don’t leave any fringe topics especially those which are not in CSE syllabus- Lagrangian and Hamiltonian mechanics, saha’s ionization, cornu’s spiral etc
    • There’ll be invariably 1-2 questions from these and if you have prepared them well, they can give you an edge.
  • Prepare revision notes (summary sheets – 3-4 pages for each units)
    • Cant emphasize the importance of this. If you don’t have these, you’ll be overwhelmed just before the exam by the sheer size of the notes.
  • For those who join DIAS
    • Attend all classes
    • Solve tutorials as per schedule
    • Give all test on time
Book list
  • Mechanics
    • JCUpadhyay
  • Optics
    • Ghatak
  • Electricity and magentism
    • Griffith and SP
  • Thermo
    • Garg, bansal, ghosh
  • Resnick and Eisberg
  • Quantum
    • HCV
  • Atomic and molecular
    • Rajkumar and ban well
  • Nuclear and Particle
    • SBPatel
  • Solid state and digital electronics
    • Puri and babbar
Please remember that this is a test of your perseverance and balanced approach and not of your smartness.

IFoS – Optional

As per current pattern one has to choose two optional for IFoS. Each of them have two paper of 200 marks each. This means both optionals together form a total of 800/1700 in your final score

From the notification, the options to choose optional are –

  • (i) Agriculture
  • (ii.) Agricultural Engineering
  • (iii)  Animal Husbandry & Veterinary Science
  • (iv)  Botany
  • (v)  Chemistry
  • (vi)  Chemical Engineering
  • (vii)  Civil Engineering
  • (viii) Forestry
  • (ix)  Geology
  • (x)  Mathematics
  • (xi)  Mechanical Engineering
  • (xii)  Physics
  • (xiii) Statistics
  • (xiv) Zoology
Provided that the candidates will not be allowed to offer the following combination of subjects :
  1. (a)  Agriculture and Agricultural Engg.
  2. (b)  Agriculture and Animal Husbandry & Veterinary Science.
  3. (c)  Agriculture and ·Forestry.
  4. (d)  Chemistry and Chemical Engg.
  5. (e)  Mathematics and Statistics.
  6. (f)  Of the Engineering subjects viz. Agricultural Engineering, Chemical Engineering, Civil Engineering and Mechanical Engineering- not more than one subject;

My 2 cents – choose your optional wisely. As far as possible – Forestry should be one of the optional. This is because if you prepare it beforehand, it will help you in prelims (environment portion), CSE mains (allelopathy type question in GS3 – 2016 paper), IFoS interview (they are definitely going to ask something from forestry even if you dont have it as an optional)