ELECTRICITY

• Electric Charge is a physical property of an object that causes to be attracted toward or repelled from another charged object.
• The electromagnetic force of each charged object generates and is influenced by a force.
• Static electricity is the buildup of electric charge on the surface of an object.
• Electron Transfer is when rubbing two materials, electrons may be transferred from one material to the other.
• When electron transfer occurs, one material ends up with an excess of electrons and become negatively charged, while the other ends up with a deficiency of electrons and becomes positively charged.
• The imbalance of charges on objects result in the phenomena we commonly refer to as static electricity.
• A person touching Van de Graaff Generator receives excess positive charge which results in the hair expanding. The repulsion of these positive-like charges causes the strands of hair to repel other strands of hair to stand up.
• Van de Graaff Generator is a static electricity generator invented by Robert Jemison Van de Graaff.
• Robert Jemison Van de Graaff designed it initially to serve as a particle accelerator.
• In 1933, he completed the Van de Graf Generator capable of producing 7 million bolts.
• A typical Van de Graaff generator produces an imbalance of charges from the interaction between its roller, belt, and metal comb assembly..
• 1. Once the motor starts, the lower roller also begins moving and rubs against the belt. The friction between the two causes electrons to jump from the belt to the roller leaving the roller negatively charged and the belt positively charged. comb, making the comb tips strongly positively charged.
• 2. The negatively charged roller repels the electrons in the metal comb, making the comb tips strongly positively charged. The electric field between the comb tips and the roller is so intense that the electrons of the nearby air molecules are stripped away, and become attracted to the positively charged metal comb.
• 3. The belt carries these positive ions to the upper section of the generator.
• 4. Once the belt reaches the upper roller, the two rub against each other, allowing the electrons from the roller to move to the positively charged belt. Consequently, the roller is left positively charged due to the loss of electrons.
• 5. The roller then attracts the electrons from the upper metal comb's tips. The massive charge imbalance creates an intense electric field between the roller and comb tips stripping away the electrons of nearby air molecules and allowing them to move toward the positively charged roller.
• 6. Positive charges build up and distribute uniformly on the surface of the sphere.
• 7. Once the amount of positively charged particles becomes too high, the sphere discharges by producing sparks and crackling sounds when a grounding rod comes close to it.
• Conductor is any substance that has free electrons and allows charge to move freely through it.
• Superconductors allow the movement of charge without any loss of energy.
• Insulators are materials that can hold electrons securely within their atomic orbits.
• ION is an atom or molecule having a positive or negative charge.
• Substances such as metals and salty water allow charges to move through them with relative ease.
• Electrons in insulators are bound in the structure and cannot move easily-as much more 1,023 times slowly than in conductors.
• Pure water and dry table salt are examples of insulators, whereas molten salt and salty water are examples of conductors.
• In general, good conductors of electricity (metals like copper, aluminum, gold, and silver) are also good heat conductors.
• •insulators of electricity (wood, plastic, and rubber) are poor conductors of electricity.
• •Superconductors examples are aluminum, niobium, magnesium diboride and etc.
•  Charging by conduction involves making the physical connection of the charged object to the neutral object
• electroscope is made with gold foil leaves hung from a conducting metal stem and is insulated from the room air in a glass-walled container.
• Charge may occur through induction which is the process by which an electrically charged object brought near a neutral object creates a charge in that object.
• Polarization is the separation of charges in an object that remains neutral. If the spheres are now separated (before the rod is pulled away), each sphere will have a net charge.
• Ground is simply a large object that serves as an almost infinite source of electrons or sink for electrons
• The mathematical formula to calculate the electrostatic force vector between two charged particles is called Coulumb's law.
• Coulumb's law, named after the French physicist Charles Coulomb (1736-1806).
• $𝑭=$$𝒌 (𝒒_𝟏 𝒒_𝟐)/𝒓^𝟐$ is the formula for coulomb's law.
• The electrostatic force (also called the Coulomb force) is defined as the amount and direction of attraction or repulsion between two charged bodies.
• The force F is inversely proportional to the distance between two objects squared (F ∝ 1/r^2 ).
• The Coulomb force is a vector quantity and is expressed in units of Newton.
• Electric field- It is an electric property associated with each point in space when charge is present in any form.