How to Prepare for Physics Optional for the UPSC Mains Exam

Physics as optional subject in UPSC

“Quantum Physics thus reveals a basic oneness of the universe.”  –  Erwin Schrodinger


One of the science related subjects in the list of optional subjects of UPSC Civil Services Examination is Physics.This subject is not as popular as geography or public administration. It can be taken up by those with a science or engineering background in college. This article talks about how to prepare for Physics optional for the UPSC mains exam.


  • Candidates with a science particularly Physics major in their graduation.
  • Candidates with engineering backgrounds at university.


Advantages of taking Physics optional

  • Being a science subject, there is no scope for interpretation. If you know the answer and can write it satisfactorily, you will get marks. Nothing is subjective here.
  • You can score through numerical problems if you practice well enough.
  • You can score well by drawing diagrams.
  • This can be your scoring point subject if you have a solid base in it.


Tips to prepare for Physics optional

  • It is very important to make the concepts clear and be good at problem-solving in order to score good marks in Physics optional.
  • One of the important parts of your answers is derivations. Assess the number of marks allocated to a question and decide if you would derive the whole equation or just give the equation. If it is a 20-marks question, you should derive the relevant equation. Analyse the space and time constraints and decide. So, practice derivations diligently since you cannot mug up all of them.
  • For Paper I, practice numerical problems sincerely. Paper II is more theory-based.
  • You must know the definitions in terms of words and equations in case of the subject.
  • In a question where a particular phenomenon is asked, you must explain the underlying physics as well rather than just write the mathematical solution.
  • You should make summary notes of every chapter. This will make your revision easier.
  • You should practise more and more questions.
  • When you give a formula, explain the units and terms used in it.


 A few important topics in IAS exam Physics optional

Physics Paper I

Section A: classical mechanics (never ignore this topic), special relativity, waves, geometric optics, physical optics.

Section B: electricity and magnetism, electromagnetic theory (scoring topic), black body radiation, thermal physics, statistical physics.

Physics Paper II

Quantum physics, modern physics, electronics


Books to refer for Physics optional for IAS mains exam

A Dictionary of Physics – Goldstein

Advanced Level Physics – Nelkon & Parker

Atomic Physics – J. B. Rajan

Electronics -Allen Mottershead

Nuclear Physics -S.B Patel

Fundamental of Magnetism electricity – B.N. Basudeva

Modern Physics – A Beiser (Concepts of modern physics), S.L. Gupta, B.S. Agarwal, J.B. Rajan

A Textbook of Sound – Khanna & Bedi

Any fundamental book on electrical engineering like B.L Theraja (Vol 1) or Vincent Del Toro

Atomic & Molecular Spectra -Rajkumar

Classical Mechanism -Gupta, Kumar & Sharma – Takewale & Puranik -H.Goldstein

Concept of Modern Physics – Arthur Beiser

Electricity & Magnetism: D.C. TAyal, B.S. Agarwal, Griffith

Electronics – Millman & Halkias, S. Ramnam, Ryder or Bolstead, Malvina

EM Theory -Chopra&Agarwal/Satya Prakash

Introduction of Electrodynamics – David Griffiths

Mechanics – D.S. Mathur, B.S. Agarwal

Mechanics – Kleppner & Kolenkow -D.S. Mathur

Nuclear Physics – D.C. Tayal

Nuclear Physics -S.B Patel

Optics – Brijlal & Subramanyam, B.S. Agarwal, Ajoy & Ghatak

Optics-Ajoy Ghatak-B.S. Agarwal

Physics Vol I&II by David Halliday and Resnick

Properties of Matter – B. Aggarwal

Quantum Mechanics – A Ghatak

Quantum Mechanics -Ghatak & Lokanathan

Quantum Physics- Resnick & Eisberg

Solid State Physics -Kittel

Special Relativity-R.Resnick -Gupta & Goyal

Statistical Physics -B.B laud

Thermal Physics – P.K Chakraborty – Satya Prakash, Singhal & Agarwal

Thermal Physics – Singal, Agarwal & Prakash, B.S. Agarwal, Shah & Srivastava

University Physics – Zemansky

Wave/Spl.Relatively – D.S. Mathur/Kleppner Kolenkow

Waves and Oscillations – Brijlal & Subramanyam, B.S. Agarwal


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