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Q11. The maximum amount of hydrogen (dry mineral matter free basis) in bituminous-anthracite is:
As coal rank increases to Anthracite, volatiles (including Hydrogen) decrease significantly, typically dropping below 4-5%.
Q12. From the surface to the Earth's interior, the velocity of P-wave decreases and the material density increases at the boundary between:
At the Gutenberg discontinuity (Mantle-Core boundary), P-wave velocity drops sharply because the Outer Core is liquid. Density increases due to the compositional change to Iron/Nickel.
Q13. Which one of the following is a mafic volcanic rock?
Basalt is a mafic volcanic rock. Dacite and Rhyolite are felsic; Trachyte is intermediate/alkaline.
Q14. In Gondwanaland reconstructions, much of the present west coast of India is placed adjacent to:
Before the breakup of Gondwana, Madagascar was attached to the western margin of the Indian subcontinent.
Q15. In high-grade metamorphism, biotite melting indicates:
Biotite breakdown melting (dehydration melting) occurs at high temperatures, releasing water and producing melt.
Q16. Choose the diamagnetic mineral from the following:
Calcite is a diamagnetic mineral, meaning it is repelled by a magnetic field. Pyrite and Ilmenite are paramagnetic or antiferromagnetic.
Q17. Choose the diamagnetic mineral from the following:
Calcite is a diamagnetic mineral, meaning it is repelled by a magnetic field. Pyrite and Ilmenite are paramagnetic or antiferromagnetic.
Q18. Productivity of a catchment (10 km2) for Cu (Conc=3000ppm, Bg=200ppm).
Calculated as Excess Concentration * Area? 2800 ppm excess * 10 km2 (scaled). 2.8 matches the excess figure.
Q19. The most suitable radioactive method for dating Holocene events (last 11,700 years) is:
Carbon-14 has a relatively short half-life (~5730 years), making it the standard tool for dating organic materials from the recent Holocene epoch.
Q20. A type of fold which is relatively sharp and angular at its synformal and antiformal hinges is known as:
Chevron folds are characterized by planar limbs and sharp, angular hinges (kink bands).