Electricity and Magnetism – Core Vocabulary

30 vocabulary flashcards covering key terms and definitions from the lecture on electric charge, Coulomb’s law, methods of charging, properties of conductors and insulators, and electric fields.

Electric Charge

A property of matter resulting from an excess or deficiency of electrons; measured in coulombs (C).

Like Charges

Charges with the same sign (+/+ or −/−) that repel each other.

Opposite Charges

Charges with different signs (+/−) that attract each other.

Electron

Negatively charged sub-atomic particle that can move between objects during charging.

Proton

Positively charged sub-atomic particle located in the nucleus; same magnitude of charge as an electron but opposite sign.

Neutron

Electrically neutral sub-atomic particle found in the nucleus with mass similar to a proton.

Neutral Atom

Atom containing equal numbers of protons and electrons, resulting in zero net charge.

Coulomb (C)

SI unit of electric charge; 1 C equals the charge of 6.25 × 10¹⁸ electrons.

Coulomb’s Law

F = k·|q₁q₂|/d²; describes the magnitude of the electric force between two point charges.

Coulomb Constant (k)

9.0 × 10⁹ N·m²/C²; proportionality constant in Coulomb’s law.

Electric Force

Attractive or repulsive interaction between two charged objects; a long-range force needing no contact.

Electric Field (E)

Region around a charge where another charge experiences a force; E = k·Q/d² or E = F/q.

Field Lines (Lines of Force)

Pictorial representation of an electric field; originate on positive charges and terminate on negative charges, never crossing.

Electric Field Direction

Defined as the direction a positive test charge would move in the field.

Static Electricity

Electrical phenomena associated with charges at rest, typically on insulating materials.

Conductor

Material in which electrons move freely, allowing charge to distribute over the surface.

Insulator

Material in which electrons are tightly bound, keeping charge localized.

Valence Electrons

Outer electrons of an atom that are most easily removed or shifted during charging.

Charging by Friction

Transfer of electrons between objects that are rubbed together, following the electrostatic series.

Electrostatic Series

Ordered list of materials ranked by their tendency to gain or lose electrons during frictional charging.

Charging by Conduction (Contact)

Charging a neutral object by touching it with a charged object, allowing electron transfer.

Charging by Induction

Charging a neutral object without contact by rearranging its electrons using a nearby charged object; may be temporary or permanent if grounded.

Grounding

Providing a path to Earth so excess electrons can move away, often used in induction charging.

Principle of Conservation of Charge

Total electric charge in an isolated system remains constant; electrons are transferred, not created or destroyed.

Test Charge

Small, hypothetical positive charge used to probe an electric field without disturbing it significantly.

F = qE Relationship

Force on a charge in an electric field equals the product of the charge and the electric field strength.

Long-Range Force

Force, like the electric force, that acts across space without direct contact between objects.

Negatively Charged Object

Object possessing more electrons than protons due to electron gain.

Positively Charged Object

Object possessing fewer electrons than protons due to electron loss.

Polythene Rod Charging Example

When rubbed with cloth, electrons move from cloth to rod, leaving rod negatively charged.