Syllabus /

Mains Geophysics Paper-III

Stage-II (Descriptive Type)
Geophysics : Paper-III

A1. Radiometric and Airborne Geophysics:

Principles of radioactivity, radioactivity decay processes, units, radioactivity of rocks and minerals, Instruments, Ionization chamber, G-M counter, Scintillation counter, Gamma ray spectrometer, Radiometric prospecting for mineral exploration (Direct/Indirect applications), beach placers, titanium, zirconium and rare-earths, radon studies in seismology and environmental applications. Airborne geophysical surveys (gravity, magnetic, electromagnetic and radiometric), planning of surveys, flight path recovery methods. Applications in geological mapping, identification of structural features and altered zones.

A2. Marine Geophysics:

Salinity, temperature and density of sea water. Introduction to Sea-floor features: Physiography, divisions of sea floor, continental shelves, slopes, and abyssal plains, growth and decline of ocean basins, turbidity currents, occurrence of mineral deposits and hydrocarbons in offshore. Geophysical surveys and instrumentation: Gravity, Magnetic and electromagnetic surveys, Sonobuoy surveys, Instrumentation used in ship borne surveys, towing cable and fish, data collection and survey procedures, corrections and interpretation of data. Oceanic magnetic anomalies, VineMathews hypothesis, geomagnetic time scale and dating sea floor, Oceanic heat flow, ocean ridges, basins, marginal basins, rift valleys. Seismic surveys, energy sources, Pinger, Boomer, Sparker, Air gun, Hydrophones and steamer cabling. Data reduction and interpretation. Ocean Bottom Seismic surveys. Bathymetry, echo sounding, bathymetric charts, sea bed mapping. Navigation and Position fixing methods.

A3. Geophysical Signal Processing:

Time Series, Types of signals, sampling theorem, aliasing effect, Fourier series of periodic waveforms, Fourier transform and its properties, Discrete Fourier transform and FFT, Hilbert Transform, Convolution and Deconvolution, Auto and cross correlations, Power spectrum, Delta function, unit step function. Time domain windows, Z transform and properties, Inverse Z transform. Poles and zeroes. Principles of digital filters, types of filters: recursive, non recursive, time invariant, Chebyshev, Butterworth, moving average, amplitude and phase response of filters, low pass, band pass and high pass filters. Processing of Random signals. Improvement of signal to noise ratio, source and geophone arrays as spatial filters. Earth as low pass filter.

A4. Remote Sensing and Geohydrology:

Fundamental concepts of remote sensing, electromagnetic radiation spectrum, Interaction of electromagnetic energy and its interactions in atmosphere and surface of the earth, elements of photographic systems, reflectance and emittance, false color composites, remote sensing platforms, flight planning, geosynchronous and sun synchronous orbits, sensors, resolution, parallax and vertical exaggeration, relief displacement, mosaic, aerial photo interpretation and geological application. Fundamentals of photogrammetry, satellite remote sensing, multi-spectral scanners,
thermal scanners, microwave remote sensing, fundamental of image processing and interpretation for geological applications. Types of water bearing formations, porosity, permeability, storage coefficient, specific storage, specific retention, specific yield, Different types of aquifers, vertical distribution of ground water, General flow equation; steady and unsteady flow of ground water in unconfined and confined aquifers.


B1. Solid State Physics and Basic Electronics

Crystalline and amorphous structure of matter; Different crystal systems, Space groups; Methods of determination of crystal structure; X-ray diffraction, Scanning and transmission electron microscopes; Band theory of solids, conductors, insulators and semiconductors; Thermal properties of solids, Specific heat: Einstein’s and Debye theory; Magnetism: dia, para and ferro; Elements of superconductivity; Meissner effect, Josephson junctions and applications; Elementary ideas about high temperature superconductivity. Semiconductor devices and circuits: Intrinsic and Extrinsic semiconductors; Devices and structures (p-n junctions, diodes, transistors, FET, JFET and MOSFET, homo and hetero junction transistors, thermistors), Device characteristics, Frequency dependence and applications. Opto-electronic devices (solar cells, photo detectors, LEDs) Operational amplifiers and their applications.

B2. Laser systems

Spontaneous and stimulated emission of radiation. Coherence, Light amplification and relation between Einstein A and B coefficients. Rate equations for three and four level systems. Lasers: Ruby, Nd-YAG, CO2, Dye, Excimer, Semiconductor. Laser cavity modes, Line shape function and full width at half maximum (FWHM) for natural broadening, collision broadening, Doppler broadening; Saturation behavior of broadened transitions, Longitudinal and transverse modes. Mode selection, ABCD matrices and cavity stability criteria for confocal resonators. Quality factor, Expression for intensity for modes oscillating at random and mode-locked in phase. Methods of Q-switching and mode locking. Optical fiber waveguides, Fiber characteristics.

B3. Digital electronics, Radar systems, Satellite communications

Digital techniques and applications: Boolean identities, de Morgan’s theorems, Logic gates and truth tables; Simple logic circuits: registers, counters, comparators and similar circuits). A/D and D/A converters. Microprocessor: basics and architecture; Microcontroller basics. Combination and sequential logic circuits, Functional diagram, Timing diagram of read and write cycle, Data transfer techniques: serial and parallel. Fundamentals of digital computers. Radar systems, Signal and data processing, Surveillance radar, Tracking radar, Radar antenna parameters. Fundamentals of satellite systems, Communication and Orbiting satellites, Satellite frequency bands, Satellite orbit and inclinations. Earth station technology.

B4. Quantum Mechanics

Wave-particle duality; Wave functions in coordinate and momentum representations; Commutators and Heisenberg’s uncertainty principle; Schrodinger’s wave equation (time-dependent and timeindependent); Eigenvalue problems: particle in a box, harmonic oscillator, tunneling through a 1-D barrier; Motion in a central potential; Orbital angular momentum; Addition of angular momentum; Hydrogen atom; Matrix representation; Dirac’s bra and ket notations; Time-independent perturbation theory and applications; Variational method; WKB approximation; Time dependent perturbation theory and Fermi’s Golden Rule; Selection rules; Semi-classical theory of radiation; Elementary theory of scattering, Phase shifts, Partial waves, Born approximation; Identical particles, Pauli’s exclusion principle, Spin-statistics connection; Relativistic quantum mechanics: Klein Gordon and Dirac equations.

Combined Geo Scientist Combined Geo-Scientist (Main) Examination-2021 on 17.07.2021 to 18.07.2021 all over India - Download e-Admit Card
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Paper-I : General Studies-100 Marks-Paper-II : Core Subject-300 Marks-Main Exam-600 Marks

CGSE Preliminary Exam Date – 21st February, 2021 Main Exam Date – 17th & 18th July, 2021

Online Applications can be filled up to 27th October, 2020 Application Form containing two stages viz.Part-I and Part-II contact UPSC’s Facilitation Counter Telephone No. 011-23385271

Stage-I : 400 Marks-Stage-II : 600 Marks-Stage-III: 200 Marks

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