Glossary
Charge Transfer
The movement of electric charge, typically electrons, from one object or system to another.
Example:
When you rub a balloon on your hair, electrons move from your hair to the balloon, an example of charge transfer.
Charging by Induction
A method of charging an object without direct contact, typically involving a charged object, a neutral object, and a ground connection to facilitate charge transfer.
Example:
To charge a neutral sphere negatively using a positive rod, you would bring the rod near, ground the sphere to allow electrons to flow in, then remove the ground and the rod, completing charging by induction.
Conservation of Charge
A fundamental principle stating that the total electric charge in an isolated system remains constant; charge cannot be created or destroyed, only transferred.
Example:
In any chemical reaction or nuclear decay, the total charge before and after the event must be the same, illustrating the conservation of charge.
Contact (Charging by) / Conduction
A method of charging where a charged object touches a neutral object, directly transferring charge between them, causing both objects to acquire the same type of charge.
Example:
If a charged metal sphere touches a neutral metal sphere, charge will flow until they share the charge, demonstrating charging by contact or conduction.
Coulomb (C)
The SI unit of electric charge, representing the amount of charge transferred by a constant current of one ampere in one second.
Example:
A typical lightning bolt can transfer several Coulombs of charge from the cloud to the ground.
Electric Charge
A fundamental property of matter that governs electromagnetic interactions, causing objects to attract or repel each other electrically.
Example:
The static cling you feel after drying clothes is due to the transfer of electric charge between fabrics.
Friction (Charging by)
A method of charging where two neutral objects are rubbed together, causing electrons to transfer from one object to the other, resulting in opposite charges.
Example:
Rubbing a balloon on your hair causes electrons to transfer from your hair to the balloon, charging both by friction.
Grounding
The process of electrically connecting a charged object to a large, approximately neutral system (like the Earth) to allow excess charge to flow to or from it, neutralizing the object.
Example:
To safely discharge a charged capacitor, you can connect it to the Earth via a wire, effectively grounding it.
Induced Charge Separation
The phenomenon where an external electric field causes the positive and negative charges within a neutral object to redistribute, creating distinct regions of charge.
Example:
When a positively charged rod is brought near a neutral metal sphere, electrons in the sphere migrate towards the rod, creating an induced charge separation.
Negative Charge
One of the two types of electric charge, typically associated with electrons. Objects with like negative charges repel each other.
Example:
When you shuffle your feet on a carpet, your body can accumulate a negative charge, leading to a static shock.
Net Charge
The overall sum of positive and negative charges within an object or system.
Example:
A neutral atom has a zero net charge because it has an equal number of protons and electrons.
Polarization
The process where a charged object induces a separation of charge within a neutral object without direct contact, causing the charges within the neutral object to shift.
Example:
A charged comb can pick up small pieces of paper because it causes polarization in the paper, attracting the closer, oppositely charged side.
Positive Charge
One of the two types of electric charge, typically associated with protons. Objects with like positive charges repel each other.
Example:
A glass rod rubbed with silk often acquires a net positive charge.
Quantization of Charge
The principle that electric charge exists only in discrete, integer multiples of the elementary charge, *e*.
Example:
A charged particle cannot have a charge of 0.5e or 1.7e; its charge must be an integer multiple, illustrating the quantization of charge.