Glossary
Charge Conservation
The principle that the total electric charge in an isolated system remains constant; charge can be transferred between objects but cannot be created or destroyed.
Example:
When a glass rod is rubbed with silk, the positive charge gained by the rod equals the negative charge gained by the silk, demonstrating charge conservation.
Charge Distribution
The way electric charges arrange themselves on the surface or within a conductor, influenced by the shape of the object and the presence of other charges.
Example:
On a charged conductor, excess charges tend to reside on the outer surface, illustrating the concept of charge distribution.
Charging Methods
The various processes by which an object can acquire a net electric charge, typically involving the transfer or redistribution of electrons.
Example:
Charging methods like friction, contact, and induction are essential for understanding how objects become electrified.
Contact
A charging method where a charged object physically touches a neutral object, transferring some of its charge to the neutral object, resulting in both objects having the same type of charge.
Example:
If a negatively charged rod touches a neutral metal sphere, the sphere will also become negatively charged through contact.
Coulomb's Constant (k)
A proportionality constant in Coulomb's Law that relates the electrostatic force to the magnitudes of charges and the distance between them, with a value of approximately 8.99 × 10^9 Nm^2/C^2.
Example:
When calculating the force between two charges, the value of Coulomb's Constant (k) is always used to ensure the units are correct.
Coulomb's Law
A fundamental law stating that the electrostatic force between two point charges is directly proportional to the product of their magnitudes and inversely proportional to the square of the distance between them.
Example:
Using Coulomb's Law, one can calculate the attractive force between a proton and an electron in a hydrogen atom.
Electrons
Subatomic particles with a negative elementary charge that are responsible for the flow of electricity and are transferred during charging processes.
Example:
When you rub a balloon on your hair, electrons are transferred from your hair to the balloon, giving the balloon a negative charge.
Electrostatic Force
The attractive or repulsive force that exists between any two charged particles or objects, as described by Coulomb's Law.
Example:
The force that causes a charged balloon to stick to a wall is an electrostatic force.
Electrostatics
The branch of physics that deals with the phenomena arising from stationary or slow-moving electric charges.
Example:
Studying how a balloon sticks to a wall after being rubbed on hair is an example of electrostatics.
Friction
A charging method where two neutral objects are rubbed together, causing electrons to transfer from one object to the other, resulting in oppositely charged objects.
Example:
Rubbing a glass rod with silk causes the rod to become positively charged and the silk negatively charged due to friction.
Grounding
The process of connecting an object to the Earth, which acts as a vast reservoir of charge, allowing electrons to flow to or from the object to neutralize or charge it.
Example:
During induction, grounding a metal sphere allows excess electrons to flow into or out of the sphere, enabling it to acquire a permanent charge.
Induction
A charging method where a charged object is brought near, but not touching, a neutral object, causing charge separation (polarization). If the neutral object is then grounded, it acquires an opposite charge.
Example:
Bringing a positively charged rod near a neutral sphere and then grounding the sphere will cause the sphere to become negatively charged via induction.
Like Charges Repel
A fundamental principle of electrostatics stating that objects or particles carrying the same type of electric charge (both positive or both negative) will exert a repulsive force on each other.
Example:
If you bring two positively charged balloons close together, they will push away from each other because like charges repel.
Opposite Charges Attract
A fundamental principle of electrostatics stating that objects or particles carrying different types of electric charge (one positive and one negative) will exert an attractive force on each other.
Example:
A negatively charged comb will pull on small, neutral pieces of paper because the comb induces positive charges closer to it, and opposite charges attract.
Polarization
The separation of positive and negative charges within a neutral object when a charged object is brought nearby, without direct contact.
Example:
When a charged comb is brought near small pieces of paper, the paper experiences polarization, causing one side to become slightly positive and the other slightly negative, leading to attraction.
Protons
Subatomic particles with a positive elementary charge, located in the nucleus of an atom, which are generally immobile during typical charging processes.
Example:
Unlike electrons, protons remain fixed within the atomic nucleus and do not move between objects during charging by friction, contact, or induction.