CGPSC MAINS 2021 Paper-4

Points to Remember: Nuclear fission Nuclear chain reaction Control rods Radioactive decay Energy release mechanisms Introduction: Nuclear reactors generate immense amounts of energy through controlled nuclear reactions. Unlike chemical reactions that involve the rearrangement of atoms, nuclear reactions involve changes within the atom’s nucleus, resulting in a far greater release of energy. Einstein’s famous equation, … Read more

Points to Remember: In-situ conservation involves protecting species in their natural habitats. Ex-situ conservation involves protecting species outside their natural habitats. Both approaches are crucial for biodiversity conservation, often complementing each other. Introduction: Biodiversity loss is a significant global challenge, threatening ecosystem services and human well-being. Conservation biology employs various strategies to mitigate this loss, … Read more

Points to Remember: India’s diverse geography leads to distinct biogeographical regions. These regions are characterized by unique flora, fauna, and climatic conditions. Understanding these regions is crucial for conservation efforts. Introduction: India, a land of immense biodiversity, is geographically diverse, resulting in distinct biogeographical regions. These regions are not strictly defined political boundaries but rather … Read more

Points to Remember: Understanding of probability calculations. Application of combination formula. Accurate calculation of the total number of ways to choose 5 balls. Accurate calculation of the number of ways to choose 5 white balls. Introduction: This question requires a factual and analytical approach to determine the probability of a specific event—drawing five white balls … Read more

Points to Remember: This is a rate-based problem involving work done by individuals and their combined work rate. We need to find the combined work rate and then use it to calculate the time taken when working together. The key is to express the work rate of each individual as a fraction of the work … Read more

Points to Remember: Vedic Mathematics Sutras are a collection of 16 mathematical formulas and techniques. Nikhilam Sutra is used for multiplication, especially when numbers are close to a power of 10. Bijank is a Vedic method for checking the correctness of calculations. Introduction: Vedic Mathematics offers a unique approach to calculations, emphasizing speed and efficiency. … Read more

Points to Remember: RAM’s role in computer operation. Types of RAM. RAM’s relationship with other computer components (CPU, storage). Advantages and disadvantages of different RAM types. Future trends in RAM technology. Introduction: Random Access Memory (RAM) is a crucial component of a computer system. It’s a type of volatile memory, meaning that data stored in … Read more

Points to Remember: The Highest Common Factor (HCF) is the largest number that divides exactly into two or more numbers without leaving a remainder. Methods for finding the HCF include prime factorization and the Euclidean algorithm. Introduction: The Highest Common Factor (HCF), also known as the Greatest Common Divisor (GCD), is a fundamental concept in … Read more

Points to Remember: PN junction diode’s fundamental operation: rectification (converting AC to DC). Diverse applications stemming from its unidirectional current flow property. Specific applications in various electronic circuits and systems. Introduction: A PN junction diode is a fundamental semiconductor device formed by joining P-type and N-type semiconductor materials. This junction creates a depletion region that … Read more

Points to Remember: Transportation of gases, nutrients, and waste products. Regulation of body temperature, pH, and fluid balance. Protection against infection and blood loss. Introduction: Blood, a vital bodily fluid, is a complex connective tissue comprising various cellular components suspended in a liquid matrix called plasma. Its functions are multifaceted and crucial for maintaining homeostasis … Read more