Tag: Index
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Equilibrium
Introduction Equilibrium is a central concept in physics and chemistry, referring to the state of a system in which all competing influences are balanced. In a state of equilibrium, a system experiences no net change and appears to be static. However, this does not mean that nothing is happening, just that the various forces or…
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Entropy
Introduction Entropy is a fundamental concept in thermodynamics, often interpreted as a measure of disorder in a system. It is a state function that describes the number of microscopic configurations (microstates) that a thermodynamic system can have when in a state of thermodynamic equilibrium. Definition Entropy () is defined for an isolated system in the…
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Energy Bands
Introduction In solid state physics, energy bands are ranges of energy that an electron within a solid may have and are based on the energies of atomic orbitals. The concept of energy bands and band gaps is a central concept that helps explain the electronic properties of solids, such as conductors, insulators, and semiconductors. Atomic…
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Electromagnetic Waves
Introduction Electromagnetic waves are waves of electric and magnetic fields that propagate through space carrying electromagnetic energy. They are solutions to Maxwell’s equations and encompass a wide range of phenomena including radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. Maxwell’s Equations Maxwell’s equations describe the behavior of both the electric and magnetic…
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Electromagnetic Spectrum
Introduction The electromagnetic spectrum encompasses all types of electromagnetic radiation, ordered by frequency and wavelength. From lowest frequency (longest wavelength) to highest frequency (shortest wavelength), the spectrum includes radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. Wave Properties The basic properties of electromagnetic waves can be described by the wave equation and…
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Electromagnetic Pulse (EMP)
Introduction An Electromagnetic Pulse (EMP) is an intense burst of electromagnetic energy that can disrupt or even destroy electronic devices over a large area. EMPs can be generated by a variety of natural and man-made sources, including lightning, nuclear explosions, and specially designed electronic devices. Types of EMPs EMPs can be categorized into three types,…
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Electromagnetic Interference
Introduction Electromagnetic interference (EMI), also referred to as radio-frequency interference (RFI) when in the radio frequency spectrum, is a disturbance generated by an external source that affects an electrical circuit via electromagnetic radiation or induction. EMI can cause a range of problems, from minor annoyances like a noisy radio signal, to significant malfunctions in critical…
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Elasticity
Introduction Elasticity is a fundamental concept in physics that describes how a material returns to its original form after being deformed by an external force. This property is crucial in a wide range of fields, including engineering, materials science, and earth science. Hooke’s Law Hooke’s Law is the basic principle behind elasticity, and it states…
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Elastic Collisions
Introduction In physics, an elastic collision is an encounter between two bodies in which the total kinetic energy of the two bodies remains the same. In an idealized elastic collision, there is no net conversion of kinetic energy into other forms such as heat, noise, or potential energy. Fundamental Equations In one-dimensional elastic collisions, the…
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Einstein Field Equations
Introduction The Einstein field equations (EFE) are the cornerstone of Einstein’s theory of general relativity. They describe the fundamental interaction of gravitation as a result of spacetime being curved by matter and energy. They were first published by Einstein in 1915. The Equation The Einstein field equations can be written as: Here is the Einstein…