CGPSC MAINS 2015 Paper-4

Points to Remember: Convex mirrors provide a wider field of view than plane mirrors. Convex mirrors always produce virtual, upright, and diminished images. Introduction: A convex mirror, also known as a diverging mirror, is a spherical mirror whose reflecting surface bulges outwards. Unlike concave mirrors which can produce real and inverted images, convex mirrors always … Read more

Points to Remember: The Haber-Bosch process is the primary method for ammonia production. Temperature, pressure, and concentration directly impact the equilibrium and rate of the ammonia synthesis reaction. Optimizing these factors is crucial for efficient and economical ammonia production. Introduction: Ammonia (NH₃) is a crucial industrial chemical, primarily used in fertilizers. Its large-scale production relies … Read more

Points to Remember: Teflon’s chemical composition (polytetrafluoroethylene or PTFE) Teflon’s unique properties (non-stick, chemical resistance, high temperature resistance) Teflon’s diverse applications (cookware, industrial applications, medical applications) Potential environmental and health concerns related to Teflon Introduction: Teflon, officially known as polytetrafluoroethylene (PTFE), is a synthetic fluoropolymer of tetrafluoroethylene that has revolutionized numerous industries due to its … Read more

Points to Remember: Definition of an alloy. Examples of alloys and their constituent elements. Properties that make alloys useful. Introduction: An alloy is a metallic material composed of two or more chemical elements, where at least one element is a metal. The primary element is usually a metal, and the other elements, which may be … Read more

Points to Remember: Exothermic reactions release heat. Endothermic reactions absorb heat. The enthalpy change (ΔH) is a key indicator: negative for exothermic, positive for endothermic. Many everyday processes involve these reactions. Introduction: Chemical reactions involve the breaking and forming of chemical bonds. This process often involves a change in energy. Reactions can be classified based … Read more

Points to Remember: Oersted’s experiment demonstrated the connection between electricity and magnetism. A current-carrying wire creates a magnetic field. The direction of the magnetic field depends on the direction of the current. This discovery was a fundamental breakthrough in physics. Introduction: Hans Christian Ørsted, a Danish physicist and chemist, conducted a pivotal experiment in 1820 … Read more