CGPSC MAINS 2021 Paper-4

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: Focal length is the distance between the lens/mirror and its focal point. Radius of curvature is the distance between the lens/mirror and its center of curvature. For a spherical mirror, the focal length is half the radius of curvature. For a thin lens, the relationship is more complex and depends on the … Read more

Points to Remember: Specific resistance (resistivity) is a material property. It’s influenced by intrinsic material characteristics and external factors. Temperature plays a crucial role. Understanding resistivity is vital in material science and electrical engineering. Introduction: Specific resistance, or resistivity (ρ), is an intrinsic property of a material that quantifies how strongly it opposes the flow … Read more

Points to Remember: Alloys are mixtures of two or more elements, where at least one is a metal. The properties of an alloy differ from its constituent elements. Brass and bronze are common examples of alloys. Introduction: Alloys are materials composed of two or more chemical elements, where at least one element is a metal. … Read more

Points to Remember: Definition of chemical equilibrium. Definition of the equilibrium constant (Kc and Kp). Factors affecting equilibrium. Significance of equilibrium constant. Introduction: Chemical reactions don’t always proceed to completion. Many reactions reach a state where the rates of the forward and reverse reactions become equal, resulting in no net change in the concentrations of … Read more

Points to Remember: Rate of a chemical reaction refers to the speed at which reactants are converted into products. The rate is expressed as a change in concentration over a change in time. Units of the rate depend on the order of the reaction. Introduction: Chemical reactions are the foundation of countless processes in nature … Read more