Will you please provide me the GATE Geophysics solved papers???

This is the GATE Geophysics solved papers:

Q.1 In Mohs’ scale of hardness, how many minerals are of silicate composition?

(A) 4 (B) 5 (C) 6 (D) 7

Q.2 Which one of the following river systems forms the largest fluvio-deltaic system in the world?

(A) Mississippi–Ohio (B) Red–Mekong

(C) Ganga–Brahmaputra (D) Yellow–Ba Hoi

Q.3 Which one amongst the following rocks commonly has highest unconfined compressive strength?

(A) Coarse-grained sandstone (B) Mica schist

(C) Fossiliferous limestone (D) Massive basalt

Q.4 Eparchean unconformity separates geological units of

(A) early Archaean from late Archaean (B) Archaean from Proterozoic

(C) Proterozoic from Palaeozoic (D) Archaean from Phanerozoic

Q.5 Point bar deposit is associated with

(A) braided river (B) estuary

(C) meandering river (D) beach

Q.6 Polymetallic nodules on the ocean floor contain significant amounts of:

(A) Cu–Ni–Co (B) Pb–Zn–Ti

(C) Hg–Mo–Pt (D) U–Th–Nb

Q.7 If the rake of net slip of an inclined fault is 90°, the fault is

(A) strike-slip fault (B) dip-slip fault

(C) oblique-slip fault (D) transcurrent fault

Q.8 On a photo-scale of 1:40000, a square shaped open cast coal mine of 1 km2

of (in cm2

(A) 2.50 (B) 4.00 (C) 6.25 (D) 12.00

Q.9 Bouguer correction is applied to correct for the gravity anomaly due to mass between station

location and

(A) mean sea level (B) local datum plane

(C) base of upper crust (D) Mohorovicic discontinuity

Q.10 Which one of the following can be estimated from SP log against a saline-water saturated sandstone

formation encountered in a well?

(A) Resistivity of formation water (B) Degree of water saturation

(C) Depth of invasion (D) Permeability

Q.11 During its orbital motion around the Sun, the Earth is nearest to the Sun on

(A) March 21 (B) July 4

(C) September 23 (D) January 3


Q.12 Which one of the following can be best explored using electromagnetic method?

(A) Oil-bearing strata (B) Coal-bearing strata

(C) Disseminated sulphide deposit (D) Massive sulphide deposit

Q.13 Name the planet in the solar system which has its “day” longer than its “year”.

(A) Mercury (B) Venus

(C) Mars (D) Neptune

Q.14 The most sensitive instrument for magnetic survey is

(A) magnetic field balance (B) fluxgate magnetometer

(C) proton precession magnetometer (D) optically pumped magnetometer

Q.15 Which physical property of the medium governs the response of Ground Penetrating Radar (GPR)?

(A) Electrical conductivity (B) Electromagnetic conductivity

(C) Seismic wave velocity (D) Electrical permeability (dielectric permittivity)

Q.16 Out of the following gases which one has the highest contribution towards the greenhouse effect on

the Earth?

(A) CO2 (B) CO (C) CH4 (D) H2O

Q.17 Depth range of the ‘transition zone’ associated with phase changes in the Earth’s mantle is (in km)

(A) 35 to 150 (B) 150 to 410

(C) 410 to 660 (D) 660 to 800

Q.18 Choose the correct pair of plutonic rock and its volcanic equivalent.

(A) Gabbro–Trachyte (B) Syenite–Andesite

(C) Granite–Rhyolite (D) Granodiorite–Basalt

Q.19 Which of the following is NOT a variety of silica (SiO2)?

(A) Jasper (B) Coesite

(C) Stishovite (D) Flinkite

Q.20 Which one of these is NOT a source of sufficient water supply but can transmit certain quantity of

water on a regional scale due to leakage?

(A) Aquifer (B) Aquitard

(C) Aquiclude (D) Aquifuge

Q.21 Identify the type of fault present in the given aerial photograph.

(A) Normal fault (B) Reverse fault

(C) Left-lateral strike-slip fault (D) Right-lateral strike-slip fault

Q.22 The Jurassic stratigraphic succession of Kutch is characterized by which one of the following?

(A) Cephalopods (B) Trilobites

(C) Brachiopods (D) Graptolites

Q.23 Which one of the following mineral constituents exhibits strong absorption in the UV-blue band of

the EM spectrum due to charge transfer effect leading to colouration?

(A) Fe-O (B) Si-O (C) Al-OH (D) Mg-OH

Q.24 When did the supercontinent Pangaea begin to break up?

(A) Cenozoic (B) Mesozoic

(C) Palaeozoic (D) Proterozoic

Q.25 In which of the following localities does coal deposit occur?

(A) Dariba (B) Kudremukh

(C) Wardha (D) Rudrasagar


PART B (SECTION 1): FOR GEOLOGY CANDIDATES ONLY

Q. 26 to Q. 55 carry two marks each.

Q.26 Specific discharge of 1 cm per day is observed in a porous medium where hydraulic head difference

is 0.5 m and flow length is 20 m. Calculate the hydraulic conductivity (in m/day).

(A) 0.4 (B) 0.8 (C) 1.2 (D) 1.6

Q.27 A sandstone bed dipping 30° has an outcrop width of 20 m in a flat terrain. What is the true

thickness (in m) of the bed?

(A) 5 (B) 10 (C) 20 (D) 30

Q.28 Calculate the concentration (in ppm) of Ni in olivine that crystallizes from a basaltic magma

containing 20 ppm Ni. The partition coefficient (solid/melt) of nickel is 5.

(A) 4 (B) 20 (C) 100 (D) 500

Q.29 An analysis of augite yields 3 silicon atoms calculated on the basis of 12 oxygen atoms. If only Al

replaces Si, calculate the number of tetrahedral-Al in the mineral.

(A) 1 (B) 2 (C) 3 (D) 4

Q.30 Calculate the degree(s) of freedom of the assemblage orthopyroxene + clinopyroxene + plagioclase

+ hornblende + quartz + fluid in the chemical system CaO–FeO–MgO–Al2O3–SiO2–H2O with

pressure and temperature as physical variables.

(A) 0 (B) 1 (C) 2 (D) 3

Q.31 Ca-montmorillonite is formed by the chemical weathering of

(A) calcite (B) augite

(C) orthoclase (D) forsterite

Q.32 In which of the following crystal systems, the characteristic symmetry elements “a two-fold axis of

rotation and at least two planes of symmetry” are possible?

(A) Tetragonal (B) Hexagonal

(C) Orthorhombic (D) Monoclinic

Q.33 Determine the correctness or otherwise of the following Assertion [a] and Reason [r].

Assertion: Biaxial minerals can be pleochroic in three shades.

Reason: Biaxial minerals have three refractive indices.

(A) Both [a] and [r] are true and [r] is the correct reason for [a]

(B) [a] is true but [r] is false

(C) [a] is false but [r] is true

(D) Both [a] and [r] are true but [r] is not the correct reason for [a]

Q.34 The correct sequence of metamorphic facies with increasing depth in a subduction zone is

(A) greenschist, blueschist, eclogite (B) greenschist, eclogite, blueschist

(C) blueschist, greenschist, eclogite (D) blueschist, eclogite, greenschist


Q.35 Which one of the following basins is producing petroleum from the coal-rich reservoir rocks?

(A) Rajasthan Basin (B) Cambay Basin

(C) Cauvery Basin (D) Krishna–Godavari Basin

Q.36 A major thrust in the Himalayas has resulted in intense shearing of a zone about 0.5 km wide on

either side of the thrust leading to landslides. Which GIS function can be used to display the shear

zone?

(A) Contiguity (adjacency) (B) Spread

(C) Proximity (buffer) (D) Search

Q.37 Vertical exaggeration commonly occurs during stereo-viewing of aerial photographs. Where does it

occur?

(A) In the photographs (B) In the terrain

(C) In the stereoscope (D) In the perceptor’s mind

Q.38 A potassic ultrabasic hybrid igneous rock containing macrocrysts of olivine, Cr-rich diopside,

phlogopite and pyrope in a groundmass of serpentine, carbonate and perovskite can be named as

(A) kimberlite (B) ijolite

(C) melilitolite (D) harzburgite

Q.39 Herringbone structure is generally formed in which of the following environments?

(A) Fluvial (B) Aeolian

(C) Lacustrine (D) Tidal

Q.40 In a typical coal mine area affected by acid mine drainage, which one of the following acids will be

dominant?

(A) Nitric acid (B) Sulphuric acid

(C) Hydrochloric acid (D) Hydrofluoric acid

Q.41 Match the items in Group I with those in Group II.

Group I Group II

P. Theca 1. Trilobite

Q. Midrib 2. Brachiopod

R. Deltidium 3. Glossopteris

S. Pygidium 4. Graptolite

5. Diatoms

(A) P-3, Q-4, R-5, S-1 (B) P-4, Q-3, R-2, S-1

(C) P-5, Q-3, R-2, S-1 (D) P-2, Q-4, R-5, S-1

Q.42 Arrange the following formations sequentially from older to younger:

P. Sargur Schist

Q. Kajrahat Limestone

R. Cuddalore Sandstone

S. Umia Ammonite Bed

(A) P, S, Q, R (B) P, Q, R, S

(C) P, Q, S, R (D) Q, S, P, R


Q.43 Which of the following statements is true?

(A) Transposition foliation is an indication of superposed folding

(B) Stratigraphic information is retained in transposition structures

(C) Transposition foliation develops parallel to axial plane of tight folds

(D) Fold closures can be well identified in transposition structures

Q.44 Match the items in Group I with those in Group II.

Group I Group II

P. Churching 1. Concrete gravity dam

Q. Curtain grouting 2. Tunnelling

R. Piping 3. Cement

S. Pozzolan 4. Earth dam

(A) P-2, Q-1, R-4, S-3 (B) P-4, Q-1, R-2, S-3

(C) P-2, Q-3, R-1, S-4 (D) P-1, Q-2, R-3, S-4

Q.45 A horizontally bedded sandstone outcrop exhibits planar cross-beds at a number of places. The dip

directions of the foresets of cross-beds at these locations are:

N350°, N17°, N355°, N355°, N15°, N360°, N350°, N13°, N350°, N355°.

Find the mean palaeocurrent direction.

(A) N15° (B) N350° (C) N355° (D) N360°

Q.46 Salinity of three different fluid inclusions in H2O-NaCl system is to be determined by “heating–

freezing” experiments. The phase proportions of inclusions at room temperature are shown below:



The salinity can be determined by

(A) heating of P, freezing of Q (B) heating of Q, freezing of R

(C) freezing of P, heating of R (D) heating of all P, Q and R


Q.47 Study the map below showing elevation of selected locations and outcrops of sedimentary beds.

Which of the following statements is correct?

(A) The beds dip easterly (B) The beds dip westerly

(C) The beds dip southerly (D) The beds are folded



Q.48 Which of the following statements is true?

(A) P shows eutectic relation and Q shows high temperature limited solid solution

(B) Both P and Q show high temperature limited solid solution

(C) Both P and Q show eutectic relation

(D) P shows high temperature limited solid solution and Q shows eutectic relation

Q.49 Choose the correct statement?

(A) Solvus occurs in both P and Q

(B) Solvus is absent in both P and Q

(C) Solvus occurs in P but not in Q

(D) Solvus occurs in Q but not in P

Common Data for Questions 50 and 51:

The following figure gives Mohr envelope for a rock and Mohr circle in a particular stress condition.

Fracturing occurs when the Mohr circle touches the Mohr envelope at B.



Q.50 What type of fractures will develop in the rock?

(A) Extension fractures (B) Conjugate shear fractures

(C) Columnar fractures (D) Hybrid extension-shear fractures


Q.51 What is the dihedral angle?

(A) θ1 (B) θ2 (C) θ3 (D) θ4

Linked Answer Questions

Linked Answer Questions 52 and 53:

Q.52 Copper ore deposit with significant content of molybdenum occurs in

(A) thin layers of shale

(B) basic-ultrabasic rocks

(C) volcanogenic (rhyolitic) sedimentary rocks

(D) andesite porphyry

Q.53 An example of the above type of copper deposit is

(A) Kupfersciefer, Germany (B) Chuquicamata, Chile

(C) Kurroko, Japan (D) Sudbury, Canada

Statement for Linked Answer Questions 54 and 55:

Microfossils are widely used in palaeoceanographic studies.

Q.54 Which of the following microfossil groups is generally found in deep sea below the Carbonate

Compensation Depth?

(A) Foraminifera (B) Radiolaria

(C) Cocoliths (D) Ostracods

Q.55 What is the test composition of the microfossil group identified above?

(A) Carbonate (B) Phosphate

(C) Nitrate (D) Siliceous


PART B (SECTION 2): FOR GEOPHYSICS CANDIDATES ONLY

Q. 26 to Q. 55 carry two marks each.

Q.26 The average magnetic susceptibility of dolerite is 1400. What is its magnetic permeability in h/m?

(Give answer up to 5 decimal places)

(A) 0.00176 (B) 0.00211 (C) 0.00302 (D) 0.00354

Q.27 A small scale seismic reflection survey was conducted with a shot point located at the middle of a

500 m long geophone spread. The NMO-corrected travel times at the end of the spread were found

to be 1.227 s and 1.255 s. If the average seismic wave velocity above the reflector is 2500 m/s,

what is the dip of the reflector? (Give the value in degrees in nearest integer)

(A) 4 (B) 6 (C) 8 (D) 10

Q.28 The S-wave velocity in the lower continental crust is 6800 m/s and its density is 3380 kg/m3

its rigidity in GPa. (Give answer up to 2 decimal places)

(A) 156.29 (B) 160.21 (C) 162.34 (D) 164.11

Q.29 Given the frequency of an electromagnetic wave to be 1 kHz and ground conductivity to be 10 S/m,

calculate the skin depth. (Give answer in nearest integer, in meters)

(A) 2 (B) 3 (C) 5 (D) 8

Q.30 Based on acoustic log of a well, the transit time in a water-bearing sandstone zone is found to be 75

μs/ft. The transit time of acoustic wave through the sandstone matrix and water are 50 μs/ft and 200

μs/ft, respectively. Determine the porosity of the sandstone. (Give answer up to 2 decimal places)

(A) 0.05 (B) 0.10 (C) 0.12 (D) 0.17

Q.31 In frequency domain IP method, frequency effect is defined as

(A) (ρac - ρdc) / ρdc (B) (ρac - ρdc) / ρac

(C) (ρdc - ρac) / ρdc (D) (ρdc - ρac) / ρac

Q.32 The bright spot on a seismic reflection section in a sand-shale sequence can be seen over

(A) fresh water-bearing sand (B) saline water-bearing sand

(C) oil pool (D) gas pool

Q.33 The line joining the north and south magnetic dip poles misses the Earth’s centre by about (in km)

(A) 1000 (B) 1100 (C) 1200 (D) 1300

Q.34 For a three-layered earth with resistivities ρ1, ρ2, and ρ3, and corresponding thicknesses h1, h2, and

h3 respectively, the quantity (h1/ρ1) + (h2/ρ2) + (h3/ρ3) stands for

(A) longitudinal conductance (B) transverse resistance

(C) apparent conductance (D) apparent resistance

Q.35 The distance between the centre of the Earth and the barycentre (i.e. centre of mass of the Earth-
Moon system) is (in km)

(A) 4510 (B) 4670 (C) 4810 (D) 4860


Q.36 The change in gravity caused by Earth’s tides on the land surface in a complete tidal cycle is in the

range of (in milligal)

(A) 0.1 to 0.2 (B) 0.2 to 0.3

(C) 0.3 to 0.4 (D) 0.4 to 0.5

Q.37 Terrestrial heat flow is the product of

(A) thermal diffusivity and temperature

(B) thermal conductivity and temperature

(C) thermal diffusivity and temperature gradient

(D) thermal conductivity and temperature gradient

Q.38 According to Archie’s equation, the electrical resistivity of porous sandstone doesn’t depend on:

(A) porosity (B) nature of interstitial fluid

(C) tortuosity of pores (D) solid matrix

Q.39 Match the items in Group I with those in Group II.

Group I Group II

P. Magnetic susceptibility

Q. Airborne magnetic survey

R. Geomagnetic field

S. Proton precession magnetometer

(A) P-3, Q-4, R-2, S-1 (B) P-5, Q-2, R-4, S-3

(C) P-1, Q-4, R-1, S-5 (D) P-4, Q-3, R-3, S-1

Q.40 The NMO of a diffraction hyperbola as compared to that of a reflection hyperbola is

(A) always greater (B) always smaller

(C) random (D) same

Q.41 Which one of the following can be determined from the NMR log against sandstone?

(A) Clay content of sandstone (B) Total porosity

(C) Water-filled porosity (D) Structured water

Q.42 The peak in the response curves obtained from a geophone exhibits

(A) shift to lower frequency with increasing damping coefficient

(B) shift to higher frequency with increasing damping coefficient

(C) no shift in frequency with increasing damping coefficient

(D) increase in amplitude with increasing damping coefficient

Q.43 The solution to the purely under-determined problem Gm = d is given by

(A) (GT

(C) GT

d (B) (GT

G)-1GT

-1d (D) GT

(GGT

)

Q.44 Given the following matrix equation:

Am×n Xx×1 = bm×1,

the nature of this system of equation is

(A) over-determined if m > n (B) under-determined if m < n

(C) even-determined if m = n (D) determined by the rank of the matrix A

Q.45 Match the items in Group I with those in Group II.

Group I Group II

P. 10-4 to 1 Hz

Q. 400 to 2000 Hz

R. 20 kHz to 25 kHz

S. 25 MHz to 1.2 GHz

(A) P-2, Q-1, R-4, S-3 (B) P-3, Q-4, R-1, S-2

(C) P-1, Q-4, R-3, S-2 (D) P-3, Q-2, R-1, S-4

Q.46 Gamma-gamma log applied for estimation of formation density uses incident rays with energy in

the range of 0.5 MeV to 2.0 MeV. The interaction of such gamma rays with rocks is governed by

(A) photoelectric absorption (B) Compton scattering

(C) pair production (D) secondary emission of gamma rays

Q.47 Determine the correctness or otherwise of the following Assertion [a] and Reason [r].

Assertion: In a well-log survey using fresh-water drilling mud, an oil-bearing sandstone zone can

be identified by electrical resistivity and SP logs.

Reason: Oil has high electrical resistivity and the porous nature of sandstone is indicated by

negative SP.

(A) [a] is true but [r] is false

(B) [a] is false but [r] is true

(C) both [a] and [r] are true but [r] is not the correct reason for [a]

(D) both [a] and [r] are true and [r] is the correct reason for [a]

Common Data Questions

Common Data for Questions 48 and 49:

A signal having duration of 10 seconds is sampled at a rate of 1000 samples per second. The maximum

frequency of the sampled signal is 475 Hz.

Q.48 If the signal has been under-sampled, the maximum frequency (in Hz) of the original signal would

have been

(A) 475 (B) 500 (C) 525 (D) 550

Q.49 What is the frequency interval (in Hz) at which the spectrum of the above signal is evaluated?

(A) 0.08 (B) 0.10 (C) 0.12 (D) 0.14


In a sequence of equally thick layers in the subsurface, normally incident reflection coefficients at the three

interfaces are: 0.10, 0.15 and 0.18.

Q.50 The amplitude of primary reflection from the deepest interface is



(A) 0.184 (B) 0.174 (C) 0.165 (D) 0.156

Q.51 The amplitude of the surface multiple that arrives along with the reflection from the deepest

interface is

(A) 0.008 (B) 0.005 (C) 0.003 (D) 0.001

Linked Answer Questions

Statement for Linked Answer Questions 52 and 53:

A thick section of clean sand is identified on a suite of geophysical logs. The deep laterolog reads 4 Ohm-
m in the upper part of the section and 0.1 Ohm-m in the lower part of the section. The lower part is

interpreted to be 100% water-saturated. The resistivity of formation water obtained from SP log is

estimated to be 0.01 Ohm-m.

Q.52 The formation resistivity factor of the clean sand section is

(A) 8 (B) 10 (C) 12 (D) 14

Q.53 Based on the above result, the water saturation in the top part of the sand formation is

(A) 0.125 (B) 0.158 (C) 0.165 (D) 0.184

Statement for Linked Answer Questions 54 and 55:

The seismic slip of a fault after an earthquake is measured to be 0.5 m and the fault area is estimated to be

250 km2

. The rigidity of the medium surrounding the fault is 30 GPa.

Q.54 The seismic moment (in Nm) of the earthquake is

(A) 3.75 × 1018 (B) 3.75 × 1016 (C) 3.75 × 1014 (D) 3.75 × 1012

Q.55 Based on the above, the moment magnitude of the earthquake is

(A) 5.15 (B) 5.36 (C) 6.35 (D) 7.25



General Aptitude (GA) Questions

Q. 56 – Q. 60 carry one mark each.

Which one of the following options is the closest in meaning to the word given below?

Q.56

Pacify

(A) Excite (B) Soothe (C) Deplete (D) Tire

Choose the most appropriate pair of words from the options given below to complete the following

Q.57

sentence:

The high level of ___ of the questions in the test was ___ by an increase in the period of time

allotted for answering them.

(A) difficulty, compensated (B) exactitude, magnified

(C) aptitude, decreased (D) attitude, mitigated

Choose the grammatically CORRECT sentence:

Q.58

(A) He laid in bed till 8 o’clock in the morning.

(B) He layed in bed till 8 o’clock in the morning.

(C) He lain in bed till 8 o’clock in the morning.

(D) He lay in bed till 8 o’clock in the morning.

Which one of the parts (A, B, C, D) in the sentence contains an ERROR?

Q.59

No sooner had the doctor seen the results of the blood test, than he suggested the patient to

see the specialist.

(A) no sooner had

(B) results of the blood test

(C) suggested the patient

(D) see the specialist

Ten teams participate in a tournament. Every team plays each of the other teams twice. The total

Q.60

number of matches to be played is

(A) 20 (B) 45 (C) 60 (D) 90

Q. 61 - Q. 65 carry two marks each.

Q.61 A value of x that satisfies the equation log x + log (x – 7) = log (x + 11) + log 2 is

(A) 1 (B) 2 (C) 7 (D) 11

Let f(x) = x – [x], where x ≥ 0 and [x] is the greatest integer not larger than x. Then f(x) is a

Q.62

(A) monotonically increasing function

(B) monotonically decreasing function

(C) linearly increasing function between two integers

(D) linearly decreasing function between two integers

Ravi is taller than Arun but shorter than Iqbal. Sam is shorter than Ravi. Mohan is shorter than

Q.63

Arun. Balu is taller than Mohan and Sam. The tallest person can be

(A) Mohan (B) Ravi (C) Balu (D) Arun

A smuggler has 10 capsules in which five are filled with narcotic drugs and the rest contain the

Q.64

original medicine. All the 10 capsules are mixed in a single box, from which the customs officials

picked two capsules at random and tested for the presence of narcotic drugs. The probability that

the smuggler will be caught is

(A) 0.50 (B) 0.67 (C) 0.78 (D) 0.82

The documents expose the cynicism of the government officials – and yet as the media website

Q.65

reflects, not a single newspaper has reported on their existence.

Which one of the following inferences may be drawn with the greatest accuracy from the above

passage?

(A) Nobody other than the government officials knew about the existence of the documents.

(B) Newspapers did report about the documents but nobody cared.

(C) Media reports did not show the existence of the documents.

(D) The documents reveal the attitude of the government officials.