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

CSIR-NET2017DEC

Quiz-5

  

time limit 10 minutes

 

1. If V_m,V_o and V_i are the average P-wave velocities in the lower mantle, outer core and innercore respectively,then
   1.   V_m>V_i > V_o
   2.   V_i>V_m > V_o
   3.   V_i>V_o > V_m
   4.   V_m>V_o > V_i
2. A geophysicist travelling from the Bay of Bengal through the Ganga plain to the Himalaya, estimates the depth of Moho discontinuity.Which one of the following is the correct order of the Moho-depth estimates?
   1.   Himalaya>Gangaplain>Bay of Bengal
   2.   Bay of Bengal>Ganga plain>Himalaya
   3.   Ganga plain = Bay of Bengal = Himalaya
   4.   Ganga plain>Bay of Bengal>Himalaya
3. Which of the following layers of the earth dominantly accounts for its magnetic feild?
   1.   Innercores
   2.   Crust
   3.   Outercore
   4.   Mantle
4. Kepler's third law does not apply to the
   1.   motion of the moons around the planets
   2.   motion of artificial satellites around the earth
   3.   comets which do not re-appear
   4.   motion of planets around the sun
5. The oldest rock reported from India dates approxiametly
   1.   8000Ma
   2.   2500Ma
   3.   4500Ma
   4.   3500Ma
6. Which of the following isotopes would be the most useful to study the earth process that has time scales of 1000 years?
   1.   3H (Half life -12.5years)
   2.   14C(Half life -5740years)
   3.   210 Pb(half life-22years)
   4.   40K(Half life- 118 million years)
7. Which one of the following structures is an example of ductile deformation?
   1.   Buckle folds
   2.   Faults
   3.   Joints
   4.   Fractures
8. Compressional wave velocity is the highest in
   1.   Granite
   2.   Dunite
   3.   Syenite
   4.   Gabbro
9. Compared to the earth, Jupiter orbits around the Sun much slower because of its
   1.   Higher mass
   2.   Lower dentisy
   3.   Larger distance from the Sun
   4.   Slower rotation about its axis
10. The Paleo-Tethys sea once seperated
    1.   South America and Africa
    2.   Laurasia and Gondwanaland
    3.   North and South America
    4.   Europe and Asia
11. Andean-type mountain belts form in
    1.   Continental arcs
    2.   Island arcs
    3.   Continental collision zones
    4.   Continental rift zones
12. Youngs modulus of a rock specimen of density 2.7 gm/cc is 9.72 megabar. The longitudinal wave velocity (in km/s) in the rock is
    
    1.   4.8
    2.   5.2
    3.   6.0
    4.   7.2
13. An earthquake occurring at every 100 years, leads to a displacement of 2 m over a 40 km long fault. The corresponding shear strain accumulation rate is
    1.   0.5*10^-6
    2.   1*10^-6
    3.   1.5*10^-6
    4.   2*10^-6
14. An isotropic, homogeneous sample is subjected to uniaxial stress along the x-axis. The absolute value of the axial strain is found to be thrice the normal strain. The ratio (Vp/Vs) of the P wave and S wave velocity is
    1.   1.5
    2.   1.75
    3.   2.0
    4.   2.25
15. A planet is 11 times the radius of the Earth in size, but one-fourth in mass density. The gravity field on its surface would be around (in gals)
    1.   1600
    2.   2700
    3.   3300
    4.   3500
16. A seismic survey is carried out over a region comprising of a sequence of alternating horizontal layers of shale and sandstone, each having a thickness of 0.5 km with the shale layer at the top of the sequence. The P wave velocities in shale and sandstone are 2 km/s and 4 km/s respectively. The stacking velocity for a reflection from the base of the 5th layer from the top is
    1.   0.64 km/s
    2.   1.64 km/s
    3.   2.64 km/s
    4.   3.64 km/s