Electric Charges and Fields

These flashcards cover key vocabulary related to electric charges and fields, including definitions and important principles.

Electric Charge

A property of matter that causes it to experience a force when placed in an electric field, there are two types: positive and negative.

Electrostatics

The study of forces, fields and potentials arising from static charges.

Conductors

Materials that allow the flow of electric charge; have electrons that are free to move.

Insulators

Materials that do not allow the flow of electric charge; their electrons are tightly bound.

Electric Dipole Moment

A vector quantity defined by the product of charge and the distance separating the charges, indicating the strength and direction of an electric dipole.

Coulomb's Law

The law stating that the electric force between two charges is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.

Quantization of Charge

The principle that electric charge exists in discrete packets, typically multiples of the elementary charge (e).

Gauss's Law

The law stating that the electric flux through a closed surface is proportional to the enclosed electric charge.

Electric Field

A vector field around charged objects that exerts a force on other charged objects within the field.

Superposition Principle

The principle that the net force on a charge is the vector sum of the forces exerted by other charges no matter their positions.

Electric Field Lines

Imaginary lines used to visualize electric fields, where the direction represents the field direction and the density indicates the field strength.

Electric Flux

A measure of the amount of electric field passing through a given area, given by the dot product of the electric field and the area vector.

Permittivity of Free Space (ε0)

A constant that measures the ability of a vacuum to permit electric field lines; value is approximately $8.854 imes 10^{-12} C^2 N^{-1} m^{-2}$.

Like Charges

Charges that have the same sign (either positive or negative) and repel each other.

Unlike Charges

Charges that have opposite signs and attract each other.

Point Charge

An idealized model of a charged particle that has no spatial extent.

Torque on a Dipole in an Electric Field

The tendency of the dipole to align itself with the electric field, given by the product of the dipole moment and the electric field direction.

Surface Charge Density (σ)

Charge per unit area on a surface, measured in $C/m^2$.

Linear Charge Density (λ)

Charge per unit length along a wire, measured in $C/m$.

Volume Charge Density (ρ)

Charge per unit volume, measured in $C/m^3$.

Electric Field Strength (E)

The force experienced per unit charge at a point in space, measured in $N/C$.

Polarity of Charge

The property that indicates whether a charge is positive or negative.

Electric Neutrality

Condition where the total charge of an object or system is zero, resulting from an equal number of positive and negative charges.