GATE-2018 (24) :Wyllie – Time average equation

2018 GATE

Quiz-8

  

time limit 15 minutes

 

1. The speed of revolution of the Earth around the sun is
   1.   Maximum at Alhelion
   2.   Minimum at perihelion
   3.   Equal at Aphelion and Perihelion
   4.   Maximum at perihelion
2. Given that the velocity of P-waves in a sandstone matrix is 5600 m/s and that in oil is 1200 m/s, the velocity of P-wave propagation in oil saturated sandstone with 30% porosity is ______________ m/s, (Use Wyllie time average equation.)
   
   1.   2777m/s
   2.   2555m/s
   3.   2888m/s
   4.   2666m/s
3. Using the Gutenberg-Ritcher recurrence relationship, the mean annual rate of exceedance of the earthquake occurrence in a seismic belt is 0.3 per year for an earthquake of magnitude 6.0. The return period for an earthquake of magnitude 6.0 in this belt is _________ years.
   1.   3.33
   2.   5.33
   3.   4.33
   4.   2.33
4. A plane electromagnetic (EM) wave traveling vertically downwards with a frequency of 1000Hz in a homogeneous medium has a skin depth of 100m. The ratio of the amplitude of the EM wave at a depth of 75m with respect to the amplitude at the Earth’s surface is ______________
   
   1.   1.052
   2.   0.472
   3.   0.853
   4.   0.272
5. Which one of the following periods has the longest time duration?
   1.   Cretaceous
   2.   Ordovician
   3.   Silurian
   4.   Jurassic
6. Which one of the following statements is CORRECT?
   
   1.   Strength of a rock increases with increase in temperature.
   2.   Strength of a rock decreases with increase in confining pressure.
   3.   Strength of a rock increases with increase in strain rate.
   4.   Strength of a rock increases with increase in strain rate.
7. The P-wave velocity and the Poisson’s ratio for a homogeneous and isotropic sedimentary rock are 2500 m/s and 0.3, respectively. The S-wave velocity for the rock is ________m/s.
   
   1.   1360.50
   2.   1336.30
   3.   1380.20
   4.   1320.30
8. Pascal second is a unit of
   1.   Kinematic viscosity
   2.   Dynamic viscosity
   3.   Permeability
   4.   Seepage force
9. A gravity reading is taken in a stationary helicopter hovering 1 km above mean-sea level at a particular location. The difference in the value of g measured in the helicopter and at mean sea level vertically beneath the helicopter is ____________ mGals.
   1.   290.1
   2.   308.6
   3.   315.6
   4.   320.5
10. Given that the velocity of P-waves in a sandstone matrix is 5600m/s and that in oil is 1200m/s ,the velocity of P-wave propagation in oil saturated sandstone with 30%porosity is ____________m/s.(use wyllie time average equation.)
    1.   2666
    2.   3000
    3.   2200
    4.   2000
11. The unit of shear modulus (rigidity modulus} is
    1.   m^-1
    2.   kg m^-1 s^-2
    3.   m^2 s^-2
    4.   kg m^-2 s^-2
12. Which one of the following corrections is always added during reduction of the observed gravity data?
    
    1.   Free-air
    2.   Bouguer
    3.   Terrain
    4.   Latitude
13. The magnitudes of the total geo magnetic feild at the equator and pole are denoted by B_E and B_P, respectively.Which one of the following is TRUE
    1.   B_P =4B_E
    2.   B_P= 2B_E
    3.   B_P=B_E
    4.   B_P=1/2B_E
14. A student interpreted a four layer Schlumberger resistivity sounding data and obtained the resistivities (ρ) and thicknesses (h) as follows: ρ1 =100 ohm m, ρ2 =20 ohm m, ρ3 =1500 ohm m and ρ4 =50 ohm m; h1 =50 m, h2 =10 m and h3 =20 m. The same data is interpreted by another student who obtains ρ3 =2000 ohm m. Then, according to the principle of equivalence, the value of h3 interpreted by the second student is ________m. (All other model parameters estimated by both the students are the same.)
    
    1.   15m
    2.   25m
    3.   30m
    4.   50m
15. The apparent resistivities obtained at 0.1 Hz and 10 Hz in the frequency domain I.P. measurement are 100 ohm m and 80 ohm m, respectively. The Percentage Frequency Effect is_________.
    
    1.   25
    2.   30
    3.   20
    4.   35
16. The geoid can be best defined as
    1.   A surface over which the value of gravity is constant
    2.   An equipotential surface of gravirty of the earth
    3.   An oblate spheroid that best approximates the shape of the earth
    4.   The physical surface of the earth
17. The angle of inclination of the remnant magnetization measured on a basalt flow at a location P (28o N 850 E) is 40o. The palaeomagnetic latitude of the Basalt flow is________________ o N
    1.   30.6
    2.   10.5
    3.   22.7
    4.   40.4
18. Which one of the following geophysical methods uses the physical property 'Dielectric Constant'?
    1.   Ground penetrating radar
    2.   Self -potential
    3.   Seismic
    4.   Gravity