(Download) UPSC: Geologist Examination Papers-2019
Exam Name : UPSC Geo-Scientist and Geologist Exam 2019
Subject : Geophysics Paper - II
Year : 2019
Time Allowed : Three Hours
Maximum Marks : 200
Q1. (a) (i) A Ground-Penetrating Radar (GPR) in monostatic mode recorded a two-way travel time of 0.2985 us over a two-layered medium involving non-conducting dry soil of relative permittivity (Er = 5), overlying water table. Find the depth of water table. (Consider velocity of light in vacuum, c to be 0.3 m/ns)
(ii) A Magneto-Telluric (MT) sounding over a layered earth medium has yielded an apparent resistivity, P, of 120 2-m at a time period, T of 0.1 s for an electric field amplitude of 10 mV/km. Compute the involved magnetic field amplitude in nT.
(b) (i) State the necessary and sufficient conditions for the origin of gravity and magnetic anomalies separately.
(ii) On the basis of intensity of magnetic anomalies, distinguish between intra-basement and supra-basement anomalies. Specify their geological applications.
(c) An electrical sounding experiment using Schlumberger configuration has resulted in identical Vertical Electrical Sounding (VES) curves for the following two geoelectrical sections, A and B. Hence, estimate the thickness of sandwiched bed of geoelectric section B.