Physics

• Kirchhoff's Current Law


  The algebraic sum of all currents entering and leaving a junction must be equal to zero. Also known as Kirchhoff's junction rule (or nodal rule)
• Kirchhoff's Voltage Law


  The algebraic sum of the electromotive forces and the voltage drops in any loop must be zero. A loop is defined as a closed conducting path. Also known as Kirchhoff's loop rule.
• Magnetic Flux


  Defined as the number of magnetic field lines passing through a given closed surface
• Units of magnetic flux


  • SI unit: Weber (Wb)
  • Fundamental unit: Volt-seconds
  • CGS unit: Maxwell
• Gauss's Law for Electrostatics


  The electric flux through a surface is proportional to the electric charge enclosed by the surface
• Gauss's Law of Magnetism


  Magnetic flux through a closed surface is always zero
• Magnetism


  The ability of a magnetic material to attract other magnetic materials
• Poles


  Portions in a magnet, usually near its ends, where the magnetic force is greatest
• Magnetization


  The process of making a material temporarily or permanently magnetic
• Magnetic Field


  A vector field in the neighborhood of a magnet, electric current, or changing electric field, in which magnetic forces are observable
• Magnetism has the symbol B or H, the unit is Tesla (T), and the base unit is Newton*Second/Coulomb
• Magnetic Field Lines


  • Imaginary lines used to represent magnetic fields, describing the direction of the magnetic force on a north monopole at any given position
• Magnetic Force on Moving Charges


  F = qv ● B sinƟ, where F is the force (Lorentz force), q is the charge, v is the velocity of the charge, and B is the magnetic field
• Electromagnetic Induction


  The process by which a current can be induced to flow due to a changing magnetic field
• Faraday's Law


  Relates the rate of change of magnetic flux through a loop to the magnitude of the electro-motive force ε EE induced in the loop
• Refraction


  The bending of the path of a light wave as it passes across the boundary separating two media, caused by the change in speed experienced by a wave when it changes medium
• Snell's Law


  The relationship between the angles of incidence and refraction and the indices of refraction of the two media
• Malus' Law


  The intensity of a plane-polarized light that passes through an analyzer varies as the square of the cosine of the angle between the plane of the polarizer and the transmission axes of the analyzer
• AC Circuit


  An electrical circuit where the current regularly reverses direction and changes its value constantly with time
• DC Circuit


  A circuit where electric current flows through in one direction, commonly found in low-voltage applications powered by battery
• Reflection


  The act of light bouncing back when it hits a medium on a plane
• Refraction


  The process by which light shifts its path as it travels through a material, causing the light to bend
• Dispersion


  White light is passed through a glass prism it splits into its spectrum of colors (in order violet, indigo, blue, green, yellow, orange and red)
• Diffraction


  The bending of light around corners such that it spreads out and illuminates areas where a shadow is expected
• Huygens' Principle


  Every point on a wave front serves as a source of secondary wavelets, and the new wave front is the tangential surface to all the secondary wavelets
• Christiaan Huygens, a Dutch astronomer and physicist, proposed the Wave Theory of Light
• Postulates of General Relativity


  The global Lorentz covariance of special relativity becomes a local Lorentz covariance in the presence of matter. The presence of matter "curves" spacetime, and this curvature affects the path of free particles (and even the path of light).
• Photoelectric Effect


  When light shines on a metal, electrons can be ejected from the surface of the metal
• Photon


  Tiny particle of light that comprises waves of electromagnetic radiation
• Ray of Light


  A path a photon or a group of photons takes through space, visible as a column of light
• Beam of Light


  A group of light rays coming out from a source of Light, known as a point source
• Visible Light


  The segment of the electromagnetic spectrum that the human eye can view
• Max Planck, a German theoretical physicist, discovered quantum energy
• Quantum


  Finite packet of energy which depend on the frequency and velocity of the radiation
• Francesco Grimaldi, an Italian philosopher, discovered and coined the word diffraction
• Albert Einstein proposed a solution on the behavior of light having the characteristics of both wave and particle, introduced Photon Theory of light
• Louis de Broglie found out that the probability of finding a particle at a particular location is related to the wave associated with the particle, called "Matter Waves Theory"