Electrostatics
The study of electromagnetic phenomena that occur when there are no moving charges - i.e., after a static equilibrium has been established.
Electric Field
A vector field that conveys information about the force exerted on a charged object, consisting of a distribution of electric field vectors in the space around a charged object.
Scalar Field
A field in which the distribution of a scalar quantity (e.g., temperature or pressure) is measured at different points within a given space.
Electric Field Lines
Imaginary lines that represent the direction and relative magnitude of the electric field vectors at different points in space around a charged particle or object.
Uniform Electric Field
An electric field in which the magnitude and direction are the same at every point within the field.
Point Charge
A charged particle that is considered to have a negligible size, allowing for the calculation of the electric field it produces at different points in space.
Electrostatics
The study of electromagnetic phenomena that occur when there are no moving charges - i.e., after a static equilibrium has been established.
Coulomb's Law
States that the electrical force between two charged objects is directly proportional to the product of the quantity of charge on the objects and inversely proportional to the square of the separation distance between the two objects.
Electric Field
A vector field responsible for conveying the information for a force, which involves both magnitude and direction. It consists of a distribution of electric field vectors, one for each point in the space around a charged object.
Electric Field Lines
Curves that show the direction of an electric field when a tangent is drawn at each point.
Point Charge
A charged particle, often referred to as a point charge, used to determine the electric field at a given point. The electric field is directly away from the particle if the charge is positive and directly toward it if the charge is negative.
Principle of Superposition
The principle that states that the net electric field at a given point due to several charged particles can be found by adding the individual electric fields as vectors.
Net Electric Field
The combined electric field at a given point due to multiple charged particles, found by adding the individual electric fields as vectors.
Magnitude of Electric Field
The strength of the electric field at a given distance from a charged particle, determined by the charge of the particle and the distance from it.
Electric potential
The amount of electric potential energy per unit charge when a positive test charge is brought in from infinity.
Electric potential energy
The potential energy associated with a configuration of charged objects in an electric field.
Electric potential difference
The difference in electric potential between two points in an electric field.
Electric current
The flow of electric charge (usually electrons) through a conductor.
Electric resistance
The property of a conductor that resists the flow of electric current.
Voltage
The potential difference between two points in an electric field, measured in volts.
Kirchhoff's rules
A set of rules used to analyze complex electrical circuits, including the conservation of charge (current law) and the conservation of energy (voltage law).
Conservation of mechanical energy
The principle that the total mechanical energy of a closed system remains constant, regardless of internal changes or interactions.
Joule
The SI unit of energy, equal to the work done by a one newton force acting through a one meter distance.
Ohm's law
The relationship between voltage, current, and resistance in a circuit, given by the equation V = IR.
Electromagnetism
The combined study of electric and magnetic effects.
Magnetic field
The region around a magnet or a current-carrying wire where magnetic forces can be detected.
Magnetic force
The force exerted on a charged particle or a current-carrying wire by a magnetic field.
Magnetic field due to a current
The magnetic field produced by a current-carrying wire, which is perpendicular to the wire and forms concentric circles around it.
Torque
The turning effect or rotational force produced by a magnetic field on a current-carrying loop or coil.
Optics
The branch of physics that studies the behavior and properties of light, including its interactions with matter and the construction of instruments that use or detect it.
Law of Refraction
A basic law governing light that describes how light bends when it passes from one medium to another, such as from air to glass.
Virtual Image
An image that is formed by the apparent intersection of light rays but does not actually exist at that location. It is perceived by the brain at the location where the rays appear to come from.
Real Image
An image that can be formed on a surface, such as a card or a movie screen. It exists at the location where the light rays actually converge.
Plane Mirror
A flat reflecting surface that can reflect a beam of light in one direction. It produces virtual images that appear to be located behind the mirror.
Index of Refraction
A measure of how much a medium slows down the speed of light compared to its speed in a vacuum. It is defined as the ratio of the speed of light in a vacuum to the speed of light in the medium.
Huygens' Principle
A principle in wave theory that allows us to predict the position of a wavefront at any future time by considering the present position of the wavefront and the emission of secondary wavelets from points on the wavefront.
Law of Reflection
A basic law governing light that describes how light reflects off a surface, such as a mirror. It states that the angle of incidence is equal to the angle of reflection.
Interference
The phenomenon that occurs when two or more light waves combine to form a new wave. It can result in constructive interference (brightening) or destructive interference (darkening) depending on the phase relationship between the waves.
Phase Difference
The difference in phase between two waves. It can be measured in wavelengths, radians, or degrees and determines how the waves interfere with each other.