Upsc prelims MCQ

Statement 1: Incorrect. Mansabs were not hereditary in nature. The Mansabdari system, introduced by Akbar, was designed to prevent the formation of a feudal aristocracy. Ranks were granted by the emperor, were non-hereditary, and often involved frequent transfers or resumption of jagirs upon the mansabdar's death to ensure loyalty to the central authority. This is consistently described in historical sources as a key feature to maintain imperial control. Statement 2: Correct. The Zat rank fixed the personal status (position in the official hierarchy) of the mansabdar and also determined his salary/pay. Statement 3: Correct. The Sawar rank determined the number of cavalrymen (horsemen/sawars) the mansabdar was required to maintain and bring to service.

Q35

Option (A) - Carbonation - Incorrect Carbonation occurs when carbon dioxide from the atmosphere or soil dissolves in water and forms carbonic acid (H₂CO₃). This weak acid reacts particularly with carbonate minerals such as limestone (calcium carbonate) and helps dissolve them. Carbonation is therefore an important process in the chemical weathering of limestone, but it is not the process described in the question, where water becomes incorporated into the mineral structure during the transformation of feldspar into clay. Hence, A is incorrect. Option (B) - Oxidation - Incorrect Oxidation involves the reaction of minerals with oxygen. It is especially important in the weathering of minerals containing iron, producing iron oxides and hydroxides that often give rocks a characteristic reddish or yellowish colour. For example, iron-bearing minerals such as ferrous compounds can be oxidised to ferric compounds. Since the question is specifically referring to the addition/incorporation of water into the mineral during weathering, oxidation is not the appropriate process. Therefore, B is incorrect. Option (C) - Hydration - Correct Hydration is a chemical weathering process in which water molecules become incorporated into a mineral's structure, causing the mineral to change chemically and often physically. In the weathering of feldspar, water participates in reactions that can transform feldspar into clay minerals such as kaolinite. The key clue in the question is the addition of water to the mineral, which points directly to hydration. Therefore, C is the correct answer. Option (D) - Solution - Incorrect Solution occurs when minerals dissolve directly in water and are carried away in dissolved form. Water is particularly effective at dissolving minerals that are soluble or have been made more soluble through chemical reactions. However, in the process described in the question, the important feature is water becoming chemically incorporated into the mineral and contributing to the formation of clay, rather than simply dissolving the mineral and removing it. Therefore, D is incorrect.

Statement I - True Metamorphism is the process by which an existing rock changes because of factors such as heat, pressure and chemically active fluids, without the rock completely melting. During this process, the minerals present in the original rock may become unstable under the new conditions and undergo recrystallization or reorganize into new mineral arrangements. Importantly, the rock generally remains in the solid state. For example, limestone can recrystallize to form marble, while shale can undergo metamorphism to form rocks such as slate and schist. Therefore, Statement I is correct. Statement II - True Pressure, particularly directed pressure, can cause minerals within a metamorphic rock to become arranged in a preferred orientation. This alignment produces a planar or layered structure called foliation. With increasing metamorphic grade, minerals can also separate into distinct light and dark layers, producing banding, which is especially characteristic of rocks such as gneiss. Therefore, the statement that pressure can align minerals and produce foliation and banding is correct. Statement III - False Syenite is an igneous rock, not a metamorphic rock. It is a generally coarse-grained, intrusive igneous rock that forms when magma cools and crystallizes slowly beneath the Earth's surface. Its composition is broadly similar to granite, but syenite contains much less quartz. Therefore, it should not be classified as a metamorphic rock. Hence, Statement III is incorrect.

Explanation: Wilson's disease is a rare genetic disorder where the body cannot eliminate excess Copper, leading to its toxic accumulation in vital organs like the liver, brain, and eyes (forming Kayser-Fleischer rings). Option (A) Magnesium: Excess magnesium (Hypermagnesemia) is rare but can cause low blood pressure and respiratory distress; deficiency causes muscle cramps. Option (B) Potassium: Imbalances lead to Hyperkalemia (high potassium) or Hypokalemia (low potassium), both of which severely affect heart rhythms. Option (D) Sodium: High levels lead to Hypernatremia (often causing high blood pressure), while low levels cause Hyponatremia (leading to cellular swelling and confusion).