Calculation of true thickness of the bed

CSIR-NET2017DEC

Quiz-5

  

time limit 10 minutes

1 / 16

1. 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.   2.0
   2.   2.25
   3.   1.5
   4.   1.75
2. Which of the following layers of the earth dominantly accounts for its magnetic feild?
   1.   Innercores
   2.   Crust
   3.   Mantle
   4.   Outercore
3. Kepler's third law does not apply to the
   1.   motion of the moons around the planets
   2.   motion of planets around the sun
   3.   motion of artificial satellites around the earth
   4.   comets which do not re-appear
4. The oldest rock reported from India dates approxiametly
   1.   8000Ma
   2.   2500Ma
   3.   4500Ma
   4.   3500Ma
5. 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.   7.2
   2.   4.8
   3.   6.0
   4.   5.2
6. Andean-type mountain belts form in
   1.   Island arcs
   2.   Continental arcs
   3.   Continental collision zones
   4.   Continental rift zones
7. 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.   1.5*10^-6
   2.   0.5*10^-6
   3.   2*10^-6
   4.   1*10^-6
8. The Paleo-Tethys sea once seperated
   1.   Laurasia and Gondwanaland
   2.   South America and Africa
   3.   Europe and Asia
   4.   North and South America
9. 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.   2.64 km/s
   2.   0.64 km/s
   3.   1.64 km/s
   4.   3.64 km/s
10. Which one of the following structures is an example of ductile deformation?
    1.   Faults
    2.   Joints
    3.   Buckle folds
    4.   Fractures
11. 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.   2700
    2.   3500
    3.   1600
    4.   3300
12. 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.   40K(Half life- 118 million years)
    4.   210 Pb(half life-22years)
13. Compressional wave velocity is the highest in
    1.   Gabbro
    2.   Granite
    3.   Syenite
    4.   Dunite
14. Compared to the earth, Jupiter orbits around the Sun much slower because of its
    1.   Lower dentisy
    2.   Slower rotation about its axis
    3.   Higher mass
    4.   Larger distance from the Sun
15. 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.   Ganga plain = Bay of Bengal = Himalaya
    2.   Bay of Bengal>Ganga plain>Himalaya
    3.   Ganga plain>Bay of Bengal>Himalaya
    4.   Himalaya>Gangaplain>Bay of Bengal
16. 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_i>V_o > V_m
    2.   V_i>V_m > V_o
    3.   V_m>V_o > V_i
    4.   V_m>V_i > V_o