Here is the official UPSC Mechanical Engineering Optional syllabus for Paper I and Paper II, arranged paper by paper and unit by unit. Under each unit we give the official text first, then break it into numbered topics, so you can track your preparation and match every previous year question to its topic.
Source. UPSC Civil Services Examination 2026 notification (Examination Notice No. 05/2026-CSE, dated 04.02.2026, revised file of 06.02.2026, pp. 126–129), upsc.gov.in. The Mechanical Engineering syllabus has been unchanged in recent years.
Scheme. Two papers of 250 marks each (total 500), 3 hours each. Each paper has two sections (A and B) of four questions each; Questions 1 and 5 are compulsory, and three more are attempted with at least one from each section. The syllabus itself is not divided into sections. Paper I has four units (Mechanics; Engineering Materials; Theory of Machines; Manufacturing Science). Paper II has five (Thermodynamics, Gas Dynamics and Turbine; Heat Transfer; Engines; Steam Engineering; Refrigeration and Air-conditioning).
Syllabus at a glance
| Paper | Unit | Topics |
|---|---|---|
| Paper I | 1. Mechanics | 10 |
| Paper I | 2. Engineering Materials | 4 |
| Paper I | 3. Theory of Machines | 8 |
| Paper I | 4. Manufacturing Science | 17 |
| Paper II | 1. Thermodynamics, Gas Dynamics and Turbine | 8 |
| Paper II | 2. Heat Transfer | 6 |
| Paper II | 3. Engines | 5 |
| Paper II | 4. Steam Engineering | 6 |
| Paper II | 5. Refrigeration and Air-conditioning | 5 |
Paper I
1. Mechanics
Official syllabus text
1.1 Mechanics of Rigid Bodies: Equations of equilibrium in space and its application; first and second moments of area; simple problems on friction; kinematics of particles for plane motion; elementary particle dynamics.
1.2 Mechanics of Deformable Bodies: Generalized Hooke’s law and its application; design problems on axial stress, shear stress and bearing stress; material properties for dynamic loading; bending shear and stresses in beams; determination of principal stresses and strains—analytical and graphical; compound and combined stresses; bi-axial stresses—thin walled pressure vessel; material behaviour and design factors for dynamic load; design of circular shafts for bending and torsional load only; deflection of beam for statically determinate problems; theories of failure.
1.1 Equilibrium and moments of area
- Equations of equilibrium in space and their application
- First and second moments of area
1.2 Friction
- Simple problems on friction
1.3 Kinematics and dynamics of particles
- Kinematics of particles for plane motion
- Elementary particle dynamics
1.4 Simple stresses and Hooke’s law
- Generalized Hooke’s law and its application
- Design problems on axial, shear and bearing stress
1.5 Bending and shear stresses in beams
1.6 Principal stresses and strains
- Analytical and graphical determination
- Compound and combined stresses
1.7 Thin-walled pressure vessels
- Bi-axial stresses
1.8 Design of circular shafts
- Bending and torsional load
1.9 Deflection of beams
- Statically determinate problems
1.10 Dynamic loading and theories of failure
- Material properties for dynamic loading
- Material behaviour and design factors for dynamic load
- Theories of failure
2. Engineering Materials
Official syllabus text
Basic concepts on structure of solids, common ferrous and non-ferrous materials and their applications; heat-treatment of steels; non-metals—plastics, ceramics, composite materials and nano-materials.
2.1 Structure of solids
2.2 Ferrous and non-ferrous materials
- Common ferrous and non-ferrous materials and their applications
2.3 Heat-treatment of steels
2.4 Non-metals
- Plastics
- Ceramics
- Composite materials
- Nano-materials
3. Theory of Machines
Official syllabus text
Kinematic and dynamic analysis of plane mechanisms. Cams, Gears and epicyclic gear trains, flywheels, governors, balancing of rigid rotors, balancing of single and multicylinder engines, linear vibration analysis of mechanical systems (single degree of freedom), Critical speeds and whirling of shafts.
3.1 Kinematic and dynamic analysis of plane mechanisms
3.2 Cams
3.3 Gears and gear trains
- Gears
- Epicyclic gear trains
3.4 Flywheels
3.5 Governors
3.6 Balancing
- Balancing of rigid rotors
- Balancing of single and multicylinder engines
3.7 Vibrations
- Linear vibration analysis of mechanical systems (single degree of freedom)
3.8 Critical speeds and whirling of shafts
4. Manufacturing Science
Official syllabus text
4.1 Manufacturing Process: Machine tool engineering—Merchant’s force analysis; Taylor’s tool life equation; conventional machining; NC and CNC machining process; jigs and fixtures.
Non-conventional machining—EDM, ECM, ultrasonic, water jet machining etc.; application of lasers and plasmas; energy rate calculations.
Forming and welding processes—standard processes.
Metrology—concept of fits and tolerances; tools and gauges; comparators; inspection of length; position; profile and surface finish.
4.2 Manufacturing Management: System design: factory location—simple OR models; plant layout—methods based; applications of engineering economic analysis and break-even analysis for product selection, process selection and capacity planning; predetermined time standards.
System planning: forecasting methods based on regression and decomposition, design and balancing of multi model and stochastic assembly lines; inventory management—probabilistic inventory models for order time and order quantity determination; JIT systems; strategic sourcing; managing inter plant logistics.
System operations and control: Scheduling algorithms for job shops; applications of statistical methods for product and process quality control applications of control charts for mean, range, percent defective, number of defectives and defects per unit; quality cost systems; management of resources, organizations and risks in projects.
System improvement: Implementation of systems, such as total quality management, developing and managing flexible, lean and agile Organizations.
4.1 Metal cutting and machine tools
- Merchant’s force analysis
- Taylor’s tool life equation
- Conventional machining
4.2 NC and CNC machining; jigs and fixtures
- NC and CNC machining process
- Jigs and fixtures
4.3 Non-conventional machining
- EDM, ECM, ultrasonic and water jet machining
- Application of lasers and plasmas
- Energy rate calculations
4.4 Forming processes
4.5 Welding processes
4.6 Metrology
- Fits and tolerances
- Tools and gauges
- Comparators
- Inspection of length, position, profile and surface finish
4.7 Factory location and plant layout
- Factory location—simple OR models
- Plant layout
4.8 Engineering economics and capacity planning
- Engineering economic analysis
- Break-even analysis
- Product and process selection
- Capacity planning
4.9 Predetermined time standards
4.10 Forecasting
- Regression
- Decomposition
4.11 Assembly line design and balancing
- Multi model assembly lines
- Stochastic assembly lines
4.12 Inventory management and JIT
- Probabilistic inventory models for order time and order quantity
- JIT systems
4.13 Strategic sourcing and logistics
- Strategic sourcing
- Managing inter plant logistics
4.14 Scheduling
- Scheduling algorithms for job shops
4.15 Statistical quality control
- Control charts for mean and range
- Control charts for percent defective, number of defectives and defects per unit
- Quality cost systems
4.16 Project management
- Management of resources, organizations and risks in projects
4.17 System improvement
- Total quality management
- Flexible, lean and agile organizations
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1. Thermodynamics, Gas Dynamics and Turbine
Official syllabus text
1.1 Basic concept of First-law and Second law of Thermodynamics; concept of entropy and reversibility; availability and unavailability and irreversibility.
1.2 Classification and properties of fluids; incompressible and compressible fluids flows; effect of Mach number and compressibility; continuity momentum and energy equations; normal and oblique shocks; one dimensional isentropic flow; flow of fluids in duct with frictions that transfer.
1.3 Flow through fans, blowers and compressors; axial and centrifugal flow configuration; design of fans and compressors; single problems compresses and turbine cascade; open and closed cycle gas turbines; work done in the gas turbine; reheat and regenerators.
1.1 Laws of thermodynamics
- First law
- Second law
1.2 Entropy, availability and irreversibility
- Entropy and reversibility
- Availability and unavailability
- Irreversibility
1.3 Fluid properties and flow equations
- Classification and properties of fluids
- Incompressible and compressible flows
- Continuity, momentum and energy equations
1.4 Compressible and isentropic flow
- Effect of Mach number and compressibility
- One dimensional isentropic flow
1.5 Normal and oblique shocks
1.6 Flow in ducts with friction and heat transfer
1.7 Fans, blowers and compressors
- Axial and centrifugal flow configuration
- Design of fans and compressors
- Compressor and turbine cascades
1.8 Gas turbines
- Open and closed cycle gas turbines
- Work done in the gas turbine
- Reheat and regenerators
2. Heat Transfer
Official syllabus text
2.1 Conduction heat transfer—general conduction equation—Laplace, Poisson and Fourier equations; Fourier law of conduction; one dimensional steady state heat conduction applied to simple wall, solid and hollow cylinder and spheres.
2.2 Convection heat transfer—Newton’s law of convection; free and forced convection; heat transfer during laminar and turbulent flow of an incompressible fluid over a flat plate; concepts of Nusselt number, hydrodynamic and thermal boundary layer their thickness; Prandtl number; analogy between heat and momentum transfer—Reynolds, Colburn, Prandtl analogies; heat transfer during laminar and turbulent flow through horizontal tubes; free convection from horizontal and vertical plates.
2.3 Black body radiation—basic radiation laws such as Stefan-Boltzmann, Planck distribution, Wien’s displacement etc.
2.4 Basic heat exchanger analysis; classification of heat exchangers.
2.1 Conduction
- General conduction equation—Laplace, Poisson and Fourier equations
- Fourier law of conduction
- One dimensional steady state conduction: wall, cylinder and sphere
2.2 Convection over a flat plate
- Newton’s law of convection
- Free and forced convection
- Laminar and turbulent flow over a flat plate
- Nusselt number
- Hydrodynamic and thermal boundary layers
- Prandtl number
2.3 Analogy between heat and momentum transfer
- Reynolds, Colburn and Prandtl analogies
2.4 Convection in tubes and free convection
- Laminar and turbulent flow through horizontal tubes
- Free convection from horizontal and vertical plates
2.5 Radiation
- Black body radiation
- Stefan-Boltzmann law
- Planck distribution
- Wien’s displacement law
2.6 Heat exchangers
- Basic heat exchanger analysis
- Classification of heat exchangers
3. Engines
Official syllabus text
3.1 Classification, thermodynamic cycles of operation; determination of brake power, indicated power, mechanical efficiency, heat balance sheet, interpretation of performance characteristics, petrol, gas and diesel engines.
3.2 Combustion in SI and CI engines, normal and abnormal combustion; effect of working parameters on knocking, reduction of knocking; Forms of combustion chamber for SI and CI engines; rating of fuels; additives; emission.
3.3 Different systems of IC engines—fuels; lubricating; cooling and transmission systems. Alternate fuels in IC engines.
3.1 Engine classification and cycles
- Classification of engines
- Thermodynamic cycles of operation
3.2 Engine performance
- Brake power, indicated power and mechanical efficiency
- Heat balance sheet
- Performance characteristics of petrol, gas and diesel engines
3.3 Combustion in SI and CI engines
- Normal and abnormal combustion
- Knocking and its reduction
- Forms of combustion chamber
3.4 Fuels, additives and emissions
- Rating of fuels
- Additives
- Emission
- Alternate fuels in IC engines
3.5 Engine systems
- Fuel, lubricating, cooling and transmission systems
4. Steam Engineering
Official syllabus text
4.1 Steam generation—modified Rankine cycle analysis; Modern steam boilers; steam at critical and supercritical pressures; draught equipment; natural and artificial draught; boiler fuels solid, liquid and gaseous fuels. Steam turbines—Principle; types; compounding; impulse and reaction turbines; axial thrust.
4.2 Steam nozzles—flow of steam in convergent and divergent nozzle pressure at throat for maximum discharge with different initial steam conditions such as wet, saturated and superheated, effect of variation of back pressure; supersaturated flow of steam in nozzles, Wilson line.
4.3 Rankine cycle with internal and external irreversibility; reheat factor; reheating and regeneration, methods of governing; back pressure and pass out turbines.
4.4 Steam power plants—combined cycle power generation; heat recovery steam generators (HRSG) fired and unfired, co-generation plants.
4.1 Steam generation and boilers
- Modified Rankine cycle analysis
- Modern steam boilers
- Steam at critical and supercritical pressures
- Boiler fuels
4.2 Draught
- Natural and artificial draught
- Draught equipment
4.3 Steam nozzles
- Flow in convergent and divergent nozzles
- Throat pressure for maximum discharge
- Effect of back pressure
- Supersaturated flow, Wilson line
4.4 Steam turbines
- Principle and types
- Compounding
- Impulse and reaction turbines
- Axial thrust
- Methods of governing
- Back pressure and pass out turbines
4.5 Rankine cycle, reheat and regeneration
- Internal and external irreversibility
- Reheat factor
- Reheating and regeneration
4.6 Steam power plants, combined cycle and co-generation
- Combined cycle power generation
- HRSG fired and unfired
- Co-generation plants
5. Refrigeration and Air-conditioning
Official syllabus text
5.1 Vapour compression refrigeration cycle—cycle on p-H & T-s diagrams; ecofriendly refrigerants—R 134a, 123; Systems like evaporators, condensers, compressor, expansion devices. Simple vapour absorption systems.
5.2 Psychrometry—properties; processes; charts; sensible heating and cooling; humidification and dehumidification effective temperature; air-conditioning load calculation; simple duct design.
5.1 Vapour compression refrigeration
- Cycle on p-H and T-s diagrams
- Ecofriendly refrigerants (R 134a, 123)
5.2 Refrigeration system components
- Evaporators
- Condensers
- Compressors
- Expansion devices
5.3 Vapour absorption refrigeration
5.4 Psychrometry and air-conditioning processes
- Psychrometric properties, processes and charts
- Sensible heating and cooling
- Humidification and dehumidification
- Effective temperature
5.5 Air-conditioning load and duct design
- Air-conditioning load calculation
- Simple duct design
Total: 69 numbered topics across 9 units.
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