Electricity, Magnetism, and Electromagnetism

Flashcards covering the fundamental laws of electrostatics, electrodynamics, circuit rules, magnetism, and electromagnetic devices like motors and generators.

First Law of Electrostatics

Unlike charges attract; like charges repel.

Second Law of Electrostatics

Electric charge of a conductor is concentrated along the sharpest curvature of the surface.

Third Law of Electrostatics

Electric charge distribution is uniform throughout or on the surface.

Fourth Law of Electrostatics

Electrostatic force is directly proportional to the product of the electrostatic charges and inversely proportional to the square of the distance between them.

Electrodynamics

The study of electric charges in motion, commonly recognized as electricity.

Electric current

The movement of electrons along a conductor, such as copper wire, when an electric potential is applied.

Insulator

A material, such as rubber or plastic, used to coat a conducting wire to confine electron flow and prevent shock.

Electric circuit

A closed path for electron flow created by controlling resistance and modifying a conducting wire (e.g., changing wire gauge or inserting circuit elements).

Ampere ($A$)

The unit of measurement for electric current, represented by the symbol $I$.

Volt ($V$)

The unit of measurement for electric potential, represented by the symbol $V$.

Ohm ($\Omega$)

The unit of measurement for electric resistance, represented by the symbol $R$.

Ohm's Law

The relationship describing behavior in an electric circuit: $V = IR$, where $V$ is electric potential, $I$ is current, and $R$ is resistance.

Series Circuit Resistance Rule

The total resistance ($R$) is equal to the sum of the individual resistances.

Series Circuit Current Rule

The current ($I$) through each circuit element is the same and is equal to the total circuit current.

Series Circuit Voltage Rule

The sum of the voltages ($V$) across each circuit element is equal to the total circuit voltage.

Parallel Circuit Current Rule

The sum of the currents ($I$) through each circuit element is equal to the total circuit current.

Parallel Circuit Voltage Rule

The voltage ($V$) across each circuit element is the same and is equal to the total circuit voltage.

Parallel Circuit Resistance Rule

The total resistance ($R$) is the inverse of the sum of the reciprocals of each individual resistance ($R$).

Direct current (DC)

Electric current in which electrons flow in only one direction along the conductor.

Alternating current (AC)

Electric current in which electrons oscillate back and forth.

Magnetic Field

A field created by any charged particle in motion, acting perpendicular to the motion of the particle; its intensity is represented by imaginary lines.

Non magnetic

A state of matter that is unaffected by a magnetic field.

Diamagnetic

A state of matter that is weakly repelled from both magnetic poles.

Paramagnetic

A state of matter that is weakly attracted to both magnetic poles.

Ferromagnetic

A state of matter that can be strongly magnetized.

Transformer

A device that transforms electric potential and current into higher or lower intensity; it functions only with alternating current (AC).

Faraday’s Law

The first law of electromagnetic induction; it states that current is induced in a circuit if it is in a changing magnetic field and there is relative motion.

Oersted's discovery

Found that a current induced in a conductor will create a magnetic field around it that is stronger than the Earth’s magnetic field.

Fleming’s right-hand Rule

A principle stating that if current flows in the direction of the thumb, the magnetic field will be in the direction of the fingers.

Electromagnet

A ferromagnetic core that intensifies a magnetic field, acting like a magnet with North and South poles when current flows.

AC Electric Generator

A device that converts mechanical energy into electrical energy by rotating a coil in a strong magnetic field.

Electric Motor

A device that converts electrical energy into mechanical energy using the relationship between an energized coil and a stationary magnet.

AC Induction motor

A type of motor where a ferromagnetic rotor is turned by the changing polarity of electromagnets (stators) that are often separated from the rotor by glass.