Vijay Shankar Sharma
Textbook physics terms. Not a BFUT reinterpretation. 371 terms. Textbook meanings only.
19 terms. Page 1 of 1.
em · intro
The SI unit of electrical capacitance, defined as the capacitance of a capacitor that stores one coulomb of charge when a voltage of one volt is applied across it. One farad is an unusually large amount of capacitance for practical electronic components, so capacitors are typically rated in microfarads, nanofarads, or picofarads. The unit is named after English scientist Michael Faraday.
em · intermediate
A law of electromagnetism stating that the voltage induced in a closed loop of wire is proportional to the rate of change of magnetic flux through that loop. It explains how a changing magnetic field can generate electricity, forming the basis for electric generators and transformers. Combined with Lenz's law, which gives the direction of the induced current, Faraday's law is one of the four fundamental relationships summarized in Maxwell's equations.
particle · intermediate
A category of particle that follows the Pauli exclusion principle, meaning no two identical fermions can occupy the same quantum state simultaneously. All the basic building blocks of matter, including electrons, protons, neutrons, and quarks, are fermions. Fermions have half-integer values of a quantum property called spin, distinguishing them from force-carrying bosons, which have integer spin and can share quantum states freely.
em · intermediate
A strong form of magnetism found in certain materials, such as iron, cobalt, and nickel, in which the magnetic moments of neighboring atoms align spontaneously in the same direction over small regions called domains. When these domains align with each other, the material becomes strongly magnetized and can retain magnetization even after an external field is removed. Ferromagnetism is the basis for permanent magnets and most everyday magnetic materials.
particle · intermediate
A visual and mathematical shorthand, developed by physicist Richard Feynman, used to represent and calculate the interactions between subatomic particles in quantum field theory. Straight and wavy lines represent particles, and the points where lines meet represent interactions, with each diagram corresponding to a specific mathematical term in a calculation of interaction probability. Feynman diagrams greatly simplified calculations in quantum electrodynamics and remain a standard tool throughout particle physics.
optics · intro
A technology that transmits information as pulses of light through thin, flexible strands of glass or plastic, called optical fibers, relying on total internal reflection to keep the light confined within the fiber as it travels. Fiber optic cables carry far more data over longer distances with less signal loss than traditional copper wires, forming the backbone of modern internet and telecommunications infrastructure. The technology also has applications in medical imaging and sensing.
math-methods · intermediate
A physical quantity that has a value at every point in space and time, used to describe how forces act on objects without requiring direct contact between them. Familiar examples include the gravitational field surrounding a mass, the electric field surrounding a charge, and the magnetic field surrounding a magnet or current. Modern physics treats fields as fundamental, with particles arising as excitations of underlying quantum fields.
quantum · intermediate
A fundamental dimensionless physical constant, denoted by the Greek letter alpha, that characterizes the strength of the electromagnetic interaction between charged particles, with an approximate value of 1 divided by 137. Because it combines several other fundamental constants, including the elementary charge, Planck's constant, and the speed of light, into a single pure number independent of any system of units, physicists consider it one of the most important and mysterious constants in nature, and its precise numerical value has no accepted theoretical explanation.
thermo · intro
A statement of energy conservation applied to thermodynamic systems, saying that the change in a system's internal energy equals the heat added to the system minus the work done by the system on its surroundings. It formalizes the idea that energy cannot be created or destroyed, only converted between heat, work, and stored internal energy. The first law underlies the analysis of engines, refrigerators, and virtually all thermodynamic processes.
cosmology · intermediate
A mathematical description of spacetime used as the standard framework for modern cosmology, named after Alexander Friedmann, Georges Lemaitre, Howard Robertson, and Arthur Walker, which assumes the universe is homogeneous and isotropic, meaning it looks the same at every location and in every direction on sufficiently large scales. The FLRW metric, combined with Einstein's field equations, produces the Friedmann equations that describe how the universe's expansion rate evolves over time within the Lambda-CDM model.
mechanics · intermediate
The branch of physics that studies the motion of liquids and gases and the forces acting on them, governed by equations that describe conservation of mass, momentum, and energy within a flowing fluid. Fluid dynamics explains phenomena ranging from the lift generated by an airplane wing to the flow of blood through arteries and the turbulence in a flowing river. The Navier-Stokes equations are the central mathematical description used in the field.
quantum · intro
The emission of light by a substance that has absorbed light or other electromagnetic radiation of a different, usually shorter, wavelength. Electrons in the material are excited to a higher energy state by the absorbed radiation and then quickly release the excess energy as light when they fall back down, typically within nanoseconds. Fluorescence is used in lighting, fluorescent dyes for biological imaging, and security features on currency.
optics · intro
The distance between a lens or curved mirror and the point where parallel rays of light converge after passing through or reflecting from it, called the focal point. A shorter focal length bends light more strongly and produces a wider field of view, while a longer focal length produces more magnification with a narrower field of view. Focal length is a key parameter in designing cameras, telescopes, and microscopes.
mechanics · intro
A push or pull acting on an object that can cause it to accelerate, change direction, or deform, measured in newtons. According to Newton's second law, the net force on an object equals its mass multiplied by its acceleration. Forces arise from several fundamental interactions in nature, including gravity, electromagnetism, and the strong and weak nuclear forces, and everyday forces like friction and normal force emerge from these underlying interactions.
math-methods · intermediate
A mathematical technique that decomposes a signal or function of time into the frequencies that make it up, expressing a complex waveform as a combination of simple sine and cosine waves. It is used throughout physics and engineering to analyze sound, light, and other signals, and it plays a role in quantum mechanics, where it connects a particle's position and momentum representations. The transform is named after French mathematician Joseph Fourier.
mechanics · intro
A coordinate system and set of axes relative to which the position, velocity, and motion of objects are measured and described. Different observers in different frames of reference, particularly those moving relative to each other, can measure different values for quantities like velocity, though the laws of physics themselves remain the same in all inertial frames. Reference frames are especially important in special and general relativity, where measurements of time and space depend on the observer's frame.
mechanics · intro
The motion of an object under the influence of gravity alone, with no other forces such as air resistance acting on it. In free fall near Earth's surface, all objects accelerate downward at the same rate, about 9.8 meters per second squared, regardless of their mass, as first argued by Galileo. Astronauts in orbit experience apparent weightlessness because they, along with their spacecraft, are continuously in free fall around the Earth.
waves · intro
The number of complete cycles of a repeating event, such as a wave oscillation, that occur per unit of time, measured in hertz, where one hertz equals one cycle per second. Frequency is inversely related to wavelength for waves traveling at a fixed speed; higher frequency corresponds to shorter wavelength. For light, frequency determines color, and for sound, it determines pitch.
mechanics · intro
A force that resists the relative sliding or tendency to slide between two surfaces in contact, arising from microscopic roughness and molecular interactions between the surfaces. Static friction resists the start of motion between surfaces at rest relative to each other, while kinetic friction acts once sliding has begun and is generally weaker. Friction converts kinetic energy into heat and is essential for everyday actions like walking and driving, despite also causing energy losses in machines.