11. Induced polarization (IP) is primarily used to detect: A. Groundwater table B. Metallic minerals C. Faults D. Soil porosity Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option B Solution: IP surveys measure the delayed voltage decay in the ground and are useful in identifying disseminated metallic ores.
12. What is the unit of measurement in gravity geophysical surveys? A. Gauss B. Ohm-meter C. Milligal D. Hertz Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C Solution: Milligal (mGal) is used to express small gravitational variations in gravity surveys.
13. In seismic surveys, the term �shot point� refers to: A. Location of buried pipe B. Point where waves are reflected C. Place where seismic waves are generated D. Measurement station Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C Solution: A shot point is the location where seismic energy is introduced into the ground using explosives or mechanical sources.
14. Which of the following methods is most suitable for archaeological investigations? A. Magnetic B. Seismic refraction C. Resistivity D. Ground Penetrating Radar Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D Solution: GPR is widely used in archaeology due to its ability to resolve shallow subsurface features like walls, graves, and artifacts.
15. What does a Bouguer anomaly represent in gravity surveys? A. Change in water content B. Difference between observed and theoretical gravity C. Fault zone D. Fracture density Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option B Solution: A Bouguer anomaly is the corrected gravity reading that helps identify subsurface density variations like cavities, faults, or denser rock bodies.
16. Which geophysical method uses natural voltage differences to study subsurface? A. Self-potential method B. Resistivity survey C. Seismic method D. Magnetic survey Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A Solution: Self-potential (SP) method measures natural electric potentials in the ground.It�s useful in detecting groundwater flow and sulfide ore bodies.
17. In resistivity surveys, the Wenner configuration is defined by: A. Varying depth with same spacing B. Equal spacing of all electrodes C. Random electrode distances D. Alternating current sources Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option B Solution: Wenner configuration involves four electrodes placed at equal spacing and is widely used for shallow resistivity profiling.
18. What type of waves are used in seismic refraction methods? A. Electromagnetic waves B. Compressional and shear waves C. Surface water waves D. Gravity waves Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option B Solution: Seismic refraction uses P-waves and S-waves that travel through Earth materials and change speed at layer interfaces.
19. The Schlumberger array in resistivity methods is best suited for: A. Magnetic anomalies B. Deep investigations C. Surface mapping D. Microgravity studies Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option B Solution: Schlumberger array is efficient for deeper investigations as it requires fewer movements of electrodes.
20. Magnetic susceptibility depends on: A. Mineral composition B. Grain size C. Porosity D. Temperature only Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A Solution: Magnetic susceptibility reflects the ability of materials (especially iron-rich) to be magnetized.It�s directly tied to mineral composition.
