UPSC Combined Geo-Scientist Geologist 2019 Geophysics Paper I PDF

Central Government Jobs Other Jobs 2019

  • Year 2019
  • Conducted By UPSC
  • Maximum Marks 200
  • Duration Three Hours
  • Languages English

Exam Details

Detail Information
Examination Combined Geo-Scientist and Geologist Examination
Year 2019
Conducting Body UPSC
Paper Geophysics Paper I
Subject Geophysics
Duration Three Hours
Maximum Marks 200
Question Type Mixed

This is the Geophysics Paper I from the UPSC Combined Geo-Scientist and Geologist Examination held in 2019. The paper carries a maximum of 200 marks and candidates are allowed three hours to complete it. It is designed to assess candidates' knowledge in Geophysics, a crucial subject for aspiring geo-scientists and geologists. Aspirants can use this previous year's question paper for practice and to understand the exam pattern, question types, and difficulty level. The paper includes a mix of objective and descriptive questions, requiring a comprehensive understanding of geophysical principles and their applications.

Major Topics Covered

  • Radioactive Isotope Decay
  • Seismic Refraction Survey
  • Geomagnetic Field Origin
  • Earth's Core
  • Stress Tensors
  • Dipole Field
  • Covariance Matrix
  • Seismic Wave Travel Time

Why This Paper is Important

  • Useful for Combined Geo-Scientist and Geologist Exa preparation
  • Helps understand the latest exam pattern
  • Useful for practice and self-assessment
  • Covers frequently asked General Studies topics
  • Helpful for analysing question trends

Related Resources

  • UPSC Combined Geo-Scientist and Geologist Examination 2020 Geophysics Paper I
  • UPSC Combined Geo-Scientist and Geologist Examination 2018 Geophysics Paper I
  • UPSC Combined Geo-Scientist and Geologist Examination 2019 Geophysics Paper II
  • UPSC Combined Geo-Scientist and Geologist Examination 2019 Geophysics Paper I Answer Key
  • UPSC Combined Geo-Scientist and Geologist Examination Syllabus
  • Geophysics Syllabus for UPSC Exams
  • UPSC Combined Geo-Scientist and Geologist Examination Pattern
  • UPSC Exam Pattern for Geoscientist and Geologist

Instructions

  • वियोज्य DETACHABLE Combined Geo-Scientist & Geologist Exam, 2019 GEOPHYSICS Paper I Maximum Marks: 200

  • There are TEN questions divided under TWO Sections.
  • Candidate has to attempt SIX questions in all.
  • Out of the remaining EIGHT questions, FOUR questions are to be attempted choosing TWO from each Section.
  • The number of marks carried by a question/part is indicated against it.
  • Attempts of questions shall be counted in sequential order.
  • Unless struck off, attempt of a question shall be counted even if attempted partly.
  • Any page or portion of the page left blank in the answer-book must be clearly struck off.
  • Answers must be written in ENGLISH only.
  • Neat sketches may be drawn to illustrate answers, wherever required.
  • Unless otherwise mentioned, symbols and notations have their usual standard meanings.
  • Assume suitable data, if necessary and indicate the same clearly.

Questions (page 2)

Section A

Q1.

(a) How many half-lives must elapse before the activity of a radioactive isotope decreases to 2% of its initial value? How long is this time for 14C (carbon 14 isotope), which has a decay rate of 1.21 × 10-4 yr-1?

(b) The moment of the recent Indonesian earthquake has been estimated to be about 1.0 × 1023 Nm. Assume that the fault is horizontal, where slip area is 100 km wide and 1300 km long, and the shear modulus μ = 3.0 × 1010 N/m2, calculate the average displacement on the fault.

(c) Discuss about the origin of the geomagnetic field.

(d) The travel time tij measured for a seismic refraction survey over a two-layered Earth structure with velocities v0 and v1 (v1 > v0) follows the relation tij = (xij)/(v1) + Pi + qj where xij is the horizontal distance between shots (s1 & s2) and Receivers (R1, R2 & R3), Pi & qj are delay times associated with the ith shot and jth receiver positions. Formulate the problem in a standard d = Gm matrix equation, where d is the data, G is the kernel and m is the model parameter matrix.

Section A

Q2.

(a) (i) How is the Earth's core significant to the life on earth ? Explain on the basis of Geophysics and other scientific observations.
(ii) Define horizontal with respect to equipotential Earth's surface through an illustrative figure. Also explain the work done by the force \vecF, causing a displacement d\vecr in a direction making an angle θ between the two vectors \vecF & d\vecr.

(b) Assume that the horizontal component of the 2-D stress tensors are \tau = \beginbmatrix \tauxx & \tauxy \\ \tauyx & \tauyy \endbmatrix = \beginbmatrix -30 & -20 \\ -20 & -40 \endbmatrix MPa (where MPa stands for Mega Pascal)
Calculate the normal and shear stresses on a fault that strikes 15° East of North.

(c) Calculate the magnitude (Md) of the dipole field and its location (θ_d, \phid) on the Earth's surface for epoch IGRF 2000, where θ_d is the colatitude and \phid is longitude with respect to Greenwich meridian. [Use Gauss coefficients for IGRF 2000 : g10 = -29556.8 nT, g11 = -1671.7 nT, h11 = 5079.8 nT.]

Section A

Q3.

(a) Derive the expression for unit covariance matrix using the generalised inverse matrix [Gg^{-1}] and discuss its relative significance over the data and model resolution matrices.

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Frequently asked questions

What is the name of the exam?

The exam is the Combined Geo-Scientist and Geologist Examination.

Which paper is this question paper for?

This is for Geophysics Paper I.

What is the conducting body for this exam?

The exam is conducted by UPSC (Union Public Service Commission).

In which year was this exam conducted?

This exam was conducted in 2019.

What is the maximum marks for Geophysics Paper I?

The maximum marks for Geophysics Paper I is 200.

What is the time duration allowed for this paper?

The time allowed for this paper is Three Hours.

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