Discover everything you need to know about Physics optional 2025 for UPSC. Learn about the syllabus, books, notes, topper strategies, and more in this comprehensive guide.
theIAShub | 17 Feb, 2025 | 534 | 0
Physics is one of the most popular optional subjects for the UPSC Civil Services Examination, especially for candidates with a background in science or engineering. It is a subject that not only helps you understand the fundamental laws of nature but also overlaps with the General Studies papers, making it a strategic choice for many aspirants.
In this article, we will cover everything you need to know about Physics optional, including its syllabus, books, notes, previous year question papers (PYQs), topper strategies, and more. Whether you are a beginner or someone looking to refine your preparation, this guide will help you navigate through the subject with ease.
Physics as an optional subject in UPSC Mains is preferred by candidates with a strong background in science and engineering. It covers a well-defined syllabus with clear concepts, including mechanics, electromagnetism, quantum physics, and thermodynamics.
With a logical and numerical approach, it offers high-scoring potential but requires strong analytical and problem-solving skills. Here are some reasons why Physics is a great choice as an optional subject for the UPSC exam:
Physics optional syllabus in UPSC Mains covers fundamental topics such as mechanics, electricity and magnetism, quantum mechanics, and thermodynamics. It is structured into two papers, focusing on theoretical concepts and problem-solving techniques. A clear understanding of concepts and numerical proficiency is essential for effective preparation. Physics optional syllabus is divided into two papers, each covering different aspects of the subject. Here is a brief overview of the syllabus:
| Physics Optional Paper I Syllabus | ||
| PAPER-I | Topics | Details |
| 1. Mechanics of Particles | (a) Mechanics of Particles | Laws of motion; conservation of energy and momentum, applications to rotating frames, centripetal and Coriolis accelerations; Motion under a central force; Conservation of angular momentum, Kepler’s laws; Fields and potentials; Gravitational field and potential due to spherical bodies, Gauss and Poisson equations, gravitational self-energy; Two-body problem; Reduced mass; Rutherford scattering; Centre of mass and laboratory reference frames. |
| (b) Mechanics of Rigid Bodies | System of particles; Centre of mass, angular momentum, equations of motion; Conservation theorems for energy, momentum and angular momentum; Elastic and inelastic collisions; Rigid Body; Degrees of freedom, Euler’s theorem, angular velocity, angular momentum, moments of inertia, theorems of parallel and perpendicular axes, equation of motion for rotation; Molecular rotations (as rigid bodies); Di and triatomic molecules; Precessional motion; top, gyroscope. | |
| (c) Mechanics of Continuous Media | Elasticity, Hooke’s law and elastic constants of isotropic solids and their inter-relation; Streamline (Laminar) flow, viscosity, Poiseuille’s equation, Bernoulli’s equation, Stokes’ law and applications. | |
| (d) Special Relativity | Michelson-Morely experiment and its implications; Lorentz transformations length contraction, time dilation, addition of relativistic velocities, aberration and Doppler effect, mass-energy relation, simple applications to a decay process. Four-dimensional momentum vector; Covariance of equations of physics. | |
| 2. Waves and Optics | (a) Waves | Simple harmonic motion, damped oscillation, forced oscillation and resonance; Beats; Stationary waves in a string; Pulses and wave packets; Phase and group velocities; Reflection and refraction from Huygens’ principle. |
| (b) Geometrical Optics | Laws of reflection and refraction from Fermat’s principle; Matrix method in paraxial optic-thin lens formula, nodal planes, system of two thin lenses, chromatic and spherical aberrations. | |
| (c) Interference | Interference of light -Young’s experiment, Newton’s rings, interference by thin films, Michelson interferometer; Multiple beam interference and Fabry Perot interferometer. | |
| (d) Diffraction | Fraunhofer diffraction – single slit, double slit, diffraction grating, resolving power; Diffraction by a circular aperture and the Airy pattern; Fresnel diffraction: half-period zones and zone plates, circular aperture. | |
| (e) Polarisation and Modern Optics | Production and detection of linearly and circularly polarized light; Double refraction, quarter wave plate; Optical activity; Principles of fibre optics, attenuation; Pulse dispersion in step index and parabolic index fibres; Material dispersion, single mode fibers; Lasers-Einstein A and B coefficients. Ruby and He-Ne lasers. Characteristics of laser light-spatial and temporal coherence; Focusing of laser beams. Three-level scheme for laser operation; Holography and simple applications. | |
| 3. Electricity and Magnetism | (a) Electrostatics and Magnetostatics | Laplace and Poisson equations in electrostatics and their applications; Energy of a system of charges, multipole expansion of scalar potential; Method of images and its applications. Potential and field due to a dipole, force and torque on a dipole in an external field; Dielectrics, polarisation. Solutions to boundary-value problems-conducting and dielectric spheres in a uniform electric field; Magnetic shell, uniformly magnetised sphere; Ferromagnetic materials, hysteresis, energy loss. |
| (b) Current Electricity | Kirchhoff’s laws and their applications. Biot-Savart law, Ampere’s law, Faraday’s law, Lenz’ law. Self and mutual- inductances; Mean and rms values in AC circuits; DC and AC circuits with R, L and C components; Series and parallel resonance; Quality factor; Principle of transformer. | |
| 4. Electromagnetic Waves and Blackbody Radiation | – | Displacement current and Maxwell’s equations; Wave equations in vacuum, Poynting theorem; Vector and scalar potentials; Electromagnetic field tensor, covariance of Maxwell’s equations; Wave equations in isotropic dielectrics, reflection and refraction at the boundary of two dielectrics; Fresnel’s relations; Total internal reflection; Normal and anomalous dispersion; Rayleigh scattering; Blackbody radiation and Planck’s radiation law- Stefan-Boltzmann law, Wien’s displacement law and Rayleigh-Jeans law. |
| 5. Thermal and Statistical Physics | (a) Thermodynamics | Laws of thermodynamics, reversible and irreversible processes, entropy; Isothermal, adiabatic, isobaric, isochoric processes and entropy changes; Otto and Diesel engines, Gibbs’ phase rule and chemical potential; Van der Waals equation of state of a real gas, critical constants; Maxwell-Boltzmann distribution of molecular velocities, transport phenomena, equipartition and virial theorems; Dulong-Petit, Einstein, and Debye’s theories of specific heat of solids; Maxwell relations and application; Clausius-Clapeyron equation. Adiabatic demagnetisation, Joule-Kelvin effect and liquefaction of gases. |
| (b) Statistical Physics | Macro and micro states, statistical distributions, Maxwell-Boltzmann, Bose-Einstein and Fermi-Dirac Distributions, applications to specific heat of gases and blackbody radiation; Concept of negative temperatures. | |
| Physics Optional Paper II Syllabus | |
| Topic | Subtopics |
| Quantum Mechanics | – Wave-particle duality. Schrödinger equation. Wave function. Uncertainty principle.
– Solutions of the one-dimensional Schrödinger equation for free particle. Particle in a box, particle in a finite well, linear harmonic oscillator. – Reflection and transmission by a potential step and barrier. – Particle in a three-dimensional box, density of states, free electron theory of metals. – Angular momentum. Orbital angular momentum, properties of spherical harmonics. – Hydrogen atom. Spin. – Addition of angular momenta. – Pauli exclusion principle. |
| Atomic and Molecular Physics | – Quantum states of an electron in an atom. Electron spin. Spectrum of the hydrogen atom.
– Spectrum of helium and alkali atoms. Relativistic corrections for energy levels of hydrogen. – Hyperfine structure and isotopic shift. – Width of spectral lines. – LS & JJ coupling. Zeeman, Paschen-Bach and Stark effects. – Electron spin resonance. Nuclear magnetic resonance. – Basic principles of Laser action. – Properties of laser beams, coherence, and directionality. – Einstein’s A and B coefficients. – Optical pumping, population inversion. – Types of lasers: Ruby and He-Ne lasers. |
| Nuclear and Particle Physics | – Basic nuclear properties: size, shape, mass, charge distribution, spin, parity, magnetic moment.
– Binding energy, semi-empirical mass formula, and its applications. – Stability of nuclei, Fermi gas model of nucleus, liquid drop model. – Nuclear shell model. – Beta decay, gamma decay. – Nuclear reactions, Q-value, and threshold energy. – Types of nuclear reactions, conservation laws. – Particle physics: classification of fundamental forces. – Elementary particles and their quantum numbers (charge, spin, parity, isospin, strangeness, etc.). – Quark model of hadrons. – Gauge theories of fundamental forces. – Basic ideas of electroweak interaction, gluons and quark confinement. |
Physics optional books for UPSC provide comprehensive coverage of the syllabus, including fundamental concepts and advanced topics. Recommended books include standard texts like ‘Classical Mechanics’ by Goldstein and ‘Quantum Mechanics’ by Griffiths for in-depth understanding. Choosing the right books is crucial for your preparation. Here are some recommended books for Physics optional:
Preparing your own notes is one of the best ways to retain information. However, if you are short on time, you can refer to the notes provided by toppers or coaching institutes. Here are some tips for making effective notes:
The Physics optional question paper is divided into two papers, each carrying 250 marks. The questions are a mix of theoretical and analytical types. Here are some tips for attempting the question paper:
Here is a list of the last five years Geology Optional PYQ (Previous Year Question Papers) aspirants can download and use in their preparation.
| UPSC Anthropology Optional Previous Year Question Papers | |
| Year | Paper |
| 2024 | Download Paper 1 |
| Download Paper 2 | |
| 2023 | Download Paper 1 |
| Download Paper 2 | |
| 2022 | Download Paper 1 |
| Download Paper 2 | |
| 2021 | Download Paper 1 |
| Download Paper 2 | |
| 2020 | Download Paper 1 |
| Download Paper 2 | |
The Physics optional syllabus is available in PDF format on the official UPSC website. You can download it and use it as a reference for your preparation. Here are some tips for using the syllabus effectively:
If you find it challenging to prepare on your own, you can consider joining a coaching institute. Here are some benefits of joining a coaching institute:
Physics is a highly rewarding optional subject for the UPSC exam. With the right strategy, resources, and dedication, you can score well in this subject. Make sure to cover the entire syllabus, practice answer writing, and revise regularly. Use the recommended books, notes, and previous year question papers to enhance your preparation. By following these tips, you can master Physics and increase your chances of success in the UPSC exam.
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Some of the best books for Physics optional are "Classical Mechanics by Herbert Goldstein," "Thermodynamics by Enrico Fermi," and "Electromagnetism by David J. Griffiths."
To prepare for Physics optional, understand the syllabus, make a study plan, practice answer writing, and revise regularly. Use recommended books and previous year question papers.
The syllabus for Physics optional is divided into two papers: Paper-I (Classical Physics and Modern Physics) and Paper-II (Applied Physics and Advanced Topics).
To write effective answers, structure your answers well, use headings and subheadings, and support your answers with examples. Practice writing answers within the time limit.
Refine your answer writing skills and elevate your UPSC preparation with personalized support and expert feedback.
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