CGPSC MAINS 2019 Paper-4

Points to Remember: Definition and properties of alkali metals. High reactivity of alkali metals. Reasons for their non-occurrence in free state. Examples of alkali metals and their reactions. Introduction: Alkali metals are a group of chemical elements that belong to Group 1 of the periodic table. They are characterized by their highly reactive nature and … Read more

Points to Remember: Four fields where IT is used in rural sectors. Introduction: Information Technology (IT) is rapidly transforming rural areas, bridging the digital divide and fostering economic growth. While traditionally underserved, rural communities are increasingly leveraging IT for improved access to information, services, and markets. This answer will identify four key fields where IT’s … Read more

Points to Remember: Definition and types of fertilizers Sources of fertilizers (natural and synthetic) The role of fertilizers in agriculture Environmental impacts of fertilizer use Sustainable fertilizer management practices Introduction: Fertilizers are substances containing essential nutrients that are added to soil to enhance plant growth. They are crucial for boosting agricultural productivity and ensuring food … Read more

Points to Remember: Biofertilizers enhance soil fertility naturally. They are environmentally friendly alternatives to chemical fertilizers. Introduction: Biofertilizers are substances containing living microorganisms that, when applied to seeds, plant surfaces, or soil, colonize the rhizosphere (the zone of soil around plant roots) or the interior of the plant and promote growth by increasing the supply … Read more

Points to Remember: Renewable energy sources are naturally replenished over a relatively short period. Examples include solar, wind, hydro, geothermal, and biomass. Introduction: The global energy landscape is undergoing a significant transformation driven by the urgent need to mitigate climate change and ensure energy security. Renewable energy sources, unlike fossil fuels, are not finite and … Read more

Points to Remember: Definition of endemic species. Geographic distribution and factors influencing endemism. Importance of endemic species. Threats to endemic species and conservation strategies. Introduction: Endemic species are plants and animals that are found naturally in only one geographic location, such as an island, a mountain range, or a particular country. They are not found … Read more

Points to Remember: The equation involves square roots and variables. We need to isolate ‘x’ to find its value. Squaring both sides might be necessary to eliminate the square roots. We need to check for extraneous solutions after solving. Introduction: This question requires finding the value of the variable ‘x’ in the equation √(5x⁴) + … Read more

Points to Remember: Leap years have 366 days, while non-leap years have 365 days. There are 52 weeks in a year (52 x 7 = 364 days). The remaining days (1 or 2) determine whether there are 52 or 53 Sundays in a year. Introduction: Probability is a measure of the likelihood of an event … Read more

Points to Remember: Finding the Highest Common Factor (HCF) involves identifying the greatest common divisor of given numbers or expressions. Finding the Least Common Multiple (LCM) involves identifying the smallest common multiple of given numbers or expressions. For algebraic expressions, HCF and LCM involve considering the common factors of the variables and coefficients. Introduction: Subscribe … Read more

Points to Remember: The question requires identifying a pattern in a numerical series. The approach is analytical, focusing on identifying the mathematical relationship between consecutive numbers in the sequence. Introduction: This question involves identifying the next number in a given numerical series: 5, 16, 51, 158, ?. This type of question tests pattern recognition and … Read more