GATE IN Syllabus and Marks Distribution

There is no optional subject block in this paper. The syllabus defines what can be tested; it does not offer a choice to replace one subject with another. Leaving a question unanswered earns zero, but it does not reduce the set of topics that may appear.

Instrumentation Engineering Unit-wise Syllabus

Engineering Mathematics

• Linear Algebra: Matrix algebra, systems of linear equations, consistency and rank, eigenvalues and eigenvectors, tensors.
• Calculus: Functions, limits, continuity; differentiation, differentiability, partial derivatives, maxima and minima, integration, multiple integrals, vector algebra, line, surface and volume integrals, Stokes, Gauss and Green’s theorems.
• Differential Equations: Ordinary differential equations, first order linear differential equations, second order linear differential equations with constant coefficients, method of variation of parameters, Cauchy’s and Euler’s equations, initial and boundary value problems, solu tion of partial differential equations: variable separable method. Analysis of Complex Variables: Analytic functions, Cauchy’s integral theorem and integral formula, Taylor’s and Laurent’s series, residue theorem, solution of integrals.
• Probability and Statistics: Random variables, discrete and continuous distributions: normal, Poisson and Binomial distributions. Sampling from distributions, conditional probability and Bayes' theorem, mean, median, mode, standard deviation and variance.
• Numerical Methods: Solution of matrix equations, solutions of non-linear algebraic equations, iterative methods for solving differential equations, numerical integration, regression and correlation analysis, backpropagation for neural networks.

Electricity and Magnetism

• Coulomb's law, electric field intensity, electric flux density, Gauss' law, electric field and potential due to point, line, plane and spherical charge distributions, effect of dielectric medium, permittivity, capacitance, magnetic field intensity, magneti c flux density, Biot ‐Savart’s law, Ampere’s law, Faraday’s law, Lorentz force, permeability, self and mutual inductance, electrical and magnetic dipoles, electromagnetic induction, magnetomotive force, reluctance, magnetic circuits, B -H curve, Maxwell's equations: vector, dif ferential and integral forms.

Electrical Circuits and Machines

• Electrical Circuits: Independent, dependent, ideal and practical sources; V -I characteristics of practical current and voltage sources, battery, solar cell, resistor, inductor, coupled inductor, capacitor; transient analysis of RC, RL, LC, RLC circuits; power and energy consumption, power rating of components, efficiency and losses. Kirchhoff’s laws, mesh and nodal analysis, star -delta transformation, superposition, Thevenin’s, Norton’s, Miller’s, maximum power transfer and reciprocity theorems. Peak, average and rms values of AC quantities; apparent, active and reactive powers, power factor; phasor analysis, impedance and admittance; series and parallel resonance, locus diagrams, realization of basic filters with R, L, and C elements; transient analysis of RLC circuits with AC excitation. Analysis of one-port and two-port networks with controlled voltage and current sources, driving point impedance and admittance, open and short circuit parameters. Electrical Machines: Single phase transformers, permanent magnet synchronous machines; buck and boost converters, rectifiers, single phase inverters; rotor position and speed sensing, current sensing, pulse width modulation (PWM) control.

Signals and Systems

• Periodic, aperiodic and impulse signals; sampling; Fourier series, Laplace, Fourier and z -transforms, DFT and FFT; continuous -time and discrete -time systems, transfer function, linear time invariant systems, impulse response, frequency response, pulse transfer function; convolution, correlation; basics of IIR and FIR filters.

Control Systems

• Feedback principles, role of sensing in feedback, signal flow graphs, transient response, steady state error, Bode plot, phase and gain margins, Routh and Nyquist criteria, root loci, state -space representation of systems; time-delay systems.
• Actuators for control system: control valves, servo valves, servo motors, stepper motors; on -off, P, PI, PID, cascade, feed forward, and ratio controllers, tuning of PID controllers; design of lead, lag and lead -lag compensators; basic concept of supervisory control, basics of distributed control system (DCS) and programmable logic controller (PLC).

Analog Electronics

• Types of diode and their applications; BJT and MOSFET circuits, biasing, power dissipation, DC analysis, small signal analysis, frequency response of transistor circuits, feedback, amplifier design. Characteristics of ideal and practical operational amplif iers; applications of opamps : adder, subtractor, integrator, differentiator, difference amplifier, instrumentation amplifier, precision rectifier, active filters, comparators, Schmitt trigger, multivibrators, oscillators, signal generators, voltage-controlled oscillators and phase-locked loop.
• Sources and effects of noise and interference in electronic circuits; conductively, capacitively, inductively coupled interference; noise generated by electronic components, thermal noise, shot noise, flicker noise; shielding and grounding. Basic principles of component selection based on specifications, circuit board realization and testing.

Digital Electronics

• Basics of number systems. Combinational logic circuits, multiplexer and demultiplexer, truth table, minimization of Boolean functions ; IC families: ECL, TTL and CMOS , CMOS implementation of logic gates ; arithmetic circuits, sequential circuits, finite state machines, flipflops, shift registers, timers and counters.
• Analog front end: analog multiplexer, programmable gain amplifier, sample -and-hold circuit; analog-to-digital converters (ADC) (successive approximation, integrating, flash and sigma-delta) and digital-to-analog converters (DAC) (weighted R, R-2R ladder and current steering logic); characteristics and specifications of ADC and DAC (dynamic range, resolution, quantization, significant bits, conversion/settling time, INL, DNL, ENOB); embedded systems: common microprocessors and microcontrollers, memory and input -output interfacing, embedded systems programming; basics of data acquisition systems, virtual instrumentation, IoT; basic AI applications in instrumentation (sensor linearization, system calibration and tuning, signal classification).

Measurements

• SI units, standards of basic electrical quantities (R, L, C, voltage, current and frequency), systematic and random errors in measurement, expression of uncertainty, accuracy and precision, propagation of errors, linear and weighted regression ; bridges: Wheatstone, Kelvin, Maxwell, Anderson, Schering and Wien bridges for measurement of R, L, C and frequency, typical applications of bridges, Q -meter; megohm measurement; measurement of voltage, current and power in DC, single and three phase AC circuits; contact and noncontact type AC and DC current and voltage probes; true rms meters, voltage and current scaling, instrument transformers, timer/counter, time, phase and frequency measu rements, digital voltmeter, digital multimeter, digital energy meter, digital storage oscilloscope, spectrum analyzer.

Sensors and Industrial Instrumentation

• Resistive, capacitive, inductive, piezoelectric, electromagnetic and Hall effect sensors and associated signal conditioning circuits; transducers for industrial instrumentation: displacement, velocity, acceleration (linear and angular), force, torque, vibration, shock, pressure (including low and high pressure), flow (variable head, variable area, electromagnetic, ultrasonic, turbine flowmeters), temperature (thermocouple, bolometer, 2, 3, 4 wire RTD, thermistor, pyrometer and semiconductor sensor), liquid level, pH, conductivity and viscosity measurement.

Communication and Optical Instrumentation

• Amplitude and frequency modulation and demodulation, pulse code modulation, frequency and time division multiplexing; amplitude, phase, frequency, quadrature amplitude, pulse shift keying for digital modulation and demodulation; functional architectures of transmitters and receivers; instrument and sensor networks, 4 –20 mA two-wire transmitter. Optical sources and detectors: LED, laser, photo-diode, light dependent resistor, square law detectors and their characteristics; interferometer: applications in metrology; basics of fiber optic sensing. Near- infrared (NIR) sensing, Ultraviolet-Visible (UV-VIS) spectrophotometers, mass spectrometer.

General Aptitude Syllabus

General Aptitude contributes 15 marks within the 100-mark paper. It is not an additional paper that can be left out when choosing the technical sections.

Chapter-wise Weightage and Important Topics

The marks split above is fixed at section level. IIT Madras has not assigned a guaranteed number of marks to each chapter of Instrumentation Engineering. A topic may appear in one year and receive fewer questions in another; a past-paper count is not an official 2027 weightage.

For a chapter-weightage comparison, record the year, paper code, session, question number and marks of each matching question. Keep a combined question under one main topic or label the overlap explicitly; counting it twice inflates the total. GATE previous-year question papers can be used for this topic-by-topic practice.

Question Types and Negative Marking

The paper uses one-mark and two-mark questions. The number of MCQ, MSQ and NAT questions is not a fixed chapter-wise quota. In an MSQ, selecting one correct option is not enough when the correct answer contains two options.

Using the 2027 Syllabus for Preparation

Connect a sensor to its conditioning circuit and measurement error instead of learning only its operating principle. Revise transforms before solving control and signal-response problems.

Match each exercise to the current unit list. A previous-year paper may use an older scope or section code. When a current topic has no matching older question, practise that concept separately rather than deleting it from the plan. The GATE preparation plan covers full-paper practice and revision alongside topic study.

1. Unit and Topic Reference
2. Sections and Marks

1. Mathematics and General Aptitude
2. Practice and Marking Reference