Waves and Electricity: Electric Charge and Potential

Vocabulary flashcards covering the origins, properties, and fundamental laws of electric charge including conductors, insulators, and methods of charging based on the lecture notes.

Electrostatics

The branch of electricity that deals with the study of electrical phenomena associated with charges and charge systems at rest.

Elektron

The Greek word for amber, which is the origin of the term electrified, identifying a body made attractive by rubbing.

Coulomb

The S.I. unit of electric charge, defined as the amount of charge flowing through a cross-sectional area of a wire in one second when the current is one ampere.

Positive Charge

The type of electric charge that appears on a glass rod when it is rubbed with a silk cloth, as named by Benjamin Franklin.

Negative Charge

The type of electric charge that appears on a hard rubber rod when it is rubbed with fur, as named by Benjamin Franklin.

Conservation of Electric Charge

A physical principle stating that the total quantity of charge in any process does not change, meaning charges are merely transferred between bodies rather than created or destroyed.

Electrical Conductors

Materials, such as copper, aluminium, and steel, in which electric charges are free to move from place to place due to the presence of free electrons.

Free Electrons

Electrons in a conductor that are not tightly bound to the nucleus and can move freely in the spaces between positive ions in a metal lattice.

Electrical Insulators

Materials, such as polythene, cellulose acetate, glass, and paper, in which electrons are tightly held by atoms and are not free to move.

Semi-conductors

Materials like silicon and germanium that have very few free electrons at low temperatures, but whose number of free electrons increases rapidly with an increase in temperature.

Ion

An atom that has acquired a net positive or negative charge by losing or gaining one or more electrons, making it no longer electrically neutral.

Charging by Conduction

The process of charging a neutral conductor by bringing it into physical contact with a charged body, resulting in a flow of electrons between them.

Charging by Induction

The process of charging a conductor without direct contact by bringing a charged object nearby and providing a path to ground to transfer electrons.

Earthing (Grounded)

The process of connecting a conductor to the earth, which acts as a reservoir to accept or supply electrons, thereby neutralizing or setting the potential of the body.

Gold-leaf Electroscope

A device consisting of two movable gold leaves used for detecting the presence and measuring the quantity of electric charge.

Quantization of Charge

The principle that electric charge occurs only in integral amounts of a fundamental unit, represented by the formula $Q = \pm Ne$ where $N$ is an integer.

Fundamental unit of charge ($e$)

The magnitude of charge on a single proton or electron, which is equal to approximately $1.60 \times 10^{-19}\,C$.

Coulomb's Law

A fundamental law stating that the force between two point charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.