Glossary
Attraction
The electrostatic force that pulls oppositely charged objects (positive and negative) towards each other.
Example:
A positively charged proton and a negatively charged electron experience mutual attraction, pulling them together.
Charging
The process of transferring electric charge to or from an object, typically involving the movement of electrons, to give it a net positive or negative charge.
Example:
Walking across a carpet can charge your body, leading to a static shock when you touch a metal doorknob.
Conductor
A material that allows electric charge to flow freely through it, typically due to loosely bound electrons that can move easily.
Example:
Copper wires are commonly used in electrical circuits because copper is a highly efficient conductor of electricity.
Conservation of Charge
A fundamental principle stating that the total electric charge in an isolated system remains constant; charge is neither created nor destroyed, only transferred from one object to another.
Example:
When a neutral object is charged by friction, the amount of positive charge gained by one object exactly equals the amount of negative charge gained by the other, upholding the conservation of charge.
Contact (Charging by)
A method of charging where charge is transferred by direct physical touch between a charged object and a neutral object, causing the neutral object to acquire the same type of charge.
Example:
If a negatively charged comb touches a neutral metal sphere, electrons will transfer to the sphere, charging it negatively by contact.
Coulomb's Law
A quantitative law that describes the magnitude of the electrostatic force between two point charges, stating it is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.
Example:
Using Coulomb's Law, you can calculate the exact strength of the repulsive force between two charged pith balls at a given separation distance.
Electric Field
A region of space around a charged object where another charged object would experience an electric force.
Example:
A charged parallel plate capacitor creates a uniform electric field between its plates, which can accelerate charged particles.
Electric Force
The fundamental force that exists between any two charged particles, which can be either attractive (for opposite charges) or repulsive (for like charges).
Example:
The electric force between a proton and an electron is what holds atoms together.
Electrostatics
The branch of physics that studies stationary electric charges and their interactions, including the forces they exert on each other.
Example:
When you rub a balloon on your sweater and it sticks to a wall, you are observing phenomena related to electrostatics.
Friction (Charging by)
A method of charging where electrons are transferred between two different materials when they are rubbed together, resulting in one becoming positively charged and the other negatively charged.
Example:
Rubbing a glass rod with silk causes the rod to lose electrons and become positively charged through friction.
Grounding
The process of connecting a charged object to the Earth, which acts as a vast reservoir of charge, allowing excess charge to flow to or from the Earth to neutralize the object.
Example:
To safely discharge a highly charged Van de Graaff generator, you can touch it with a wire connected to the ground, effectively grounding it.
Induced Charge Separation
The process where a charged object brought near a neutral object causes the charges within the neutral object to redistribute, creating distinct positive and negative regions without direct physical contact.
Example:
Bringing a positively charged rod near a neutral aluminum can will cause the electrons in the can to shift towards the rod, demonstrating induced charge separation.
Insulator
A material that resists the flow of electric charge because its electrons are tightly bound to atoms and do not move freely.
Example:
Rubber gloves are used by electricians because rubber is an excellent insulator, preventing electric current from flowing through their bodies.
Isolated System
A system where no matter or energy, including electric charge, can enter or leave its boundaries.
Example:
A sealed, perfectly insulated container with charged particles inside could be considered an isolated system for studying charge interactions.
Polarized Object
An object that, while remaining overall electrically neutral, has its internal charges separated, creating distinct positive and negative regions due to the influence of an external electric field.
Example:
A neutral water molecule is a polarized object because its oxygen atom is slightly negative and its hydrogen atoms are slightly positive, even though the molecule has no net charge.
Repulsion
The electrostatic force that pushes similarly charged objects (both positive or both negative) away from each other.
Example:
Two positively charged balloons will exhibit repulsion, pushing each other apart when brought close.