P6

• CAPACITOR

  • An apparatus for holding electrical charge
  • Two conducting plates are placed apart by an insulating substance (such as paper, air, or oil) to form a ________.
• Vacuum or dielectric

  • an insulating substance, can be used to fill the space between the conductors.
• Capacitance

  • is the term used to describe the capacitor's capacity to hold charges.
• CAPACITOR UNIT:

  • Farads (F) or Microfarads (µF)
• TYPES OF CAPACITORS

  • Polar Capacitors
  • Non Polar Capacitors
  • Variable Capacitors
• Polar Capacitors

  • has an inherent polarity.
• Non Polar Capacitors

  • one that has no implicit polarity and can be used in either direction in a circuit.
• Variable Capacitors

  • are capacitors whose capacitance may be adjusted electrically or physically.
• Who discovered Capacitance and capacitors?

  • Ewald Georg von Kleist
  • Purrsian Scientist in 1745
  • independently by Pieter van Musschenbroek at the same time
• Ewald Georg von Kleist and Pieter van Musschenbroek

  • They discovered electricity obtain from an electrostatic machine that could be stored in a period of time and released
• Capacitance

  • in electric circuits is deliberately introduced by a device called a Capacitor
  • a property of a electric conductor, or a set of conductors that is measured by the amount of separated electric charge that can be stored on it per unit change in electrical potential
  • it is also implies an associated storage of electrical energy.
• Parallel plate capacitors

  • are electrode-insulating devices that store a finite amount of energy before dielectric breakdown. They are formed when two parallel plates are connected across a battery.
• Capacitance of a Parallel Plate Capacitor FORMULA

  
• Permittivity of space (constant)

  • ε =8.85x10^-12 F/m
• Spherical capacitors

  • consists of a solid or hollow spherical conductor, surrounded by another hollow concentric spherical of different radius.
  • consist of two concentric conducting spherical shells of radii R1 and R2. The shells are given equal and opposite charges +Q and –Q respectively. The electric field between shells is directed radially outward. The magnitude of the field can be obtained by applying Gauss law over a spherical Gaussian surface of radius r concentric with the shells.
• Capacitance of a Spherical Capacitor FORMULA

  
• Electric circuit

  • It is a complete path through which electric current flows.
  • It should be constructed in an unbroken loop.
• What makes an electric circuit complete?

  • A simple circuit consists of a battery (or other source), a light bulb (or other load) and conducting wires.
• COMPONENT

  
• SYMBOL

  
• battery

  
• closed switch

  
• open switch

  
• resistor

  
• motor

  
• fuse

  
• OHM’S LAW

  • is one of the most basic and important laws of electric circuits.
  • It is a formula used to calculate the relationship between voltage, current and resistance in an electric circuit.
• GEORG SIMON OHM (1789 - 1854)

  • A German Physicist and mathematician
  • In 1827, discovered the relationship between voltage, current, and resistance
• ELECTRICITY

  • Is a type of energy that consists of the movement of electrons between two points when there is a potential difference between them.
• ELECTRON FLOW

  • the flow of electrons from the negative terminal to the positive.
• CONVENTIONAL CURRENT

  • behaves as if positive charge carriers cause current flow.
• 3 CONCEPTS IN THE STUDY OF ELECTRICITY

  • Current
  • Voltage
  • Resistance
• Current

  • measure of how much electric charge flows through a circuit
• Voltage

  • a difference in electric potential between two points.
• Resistance

  • indicator that quantifies how readily current will flow in a circuit.
• André-Marie Ampère

  • He is a French physicist who founded and named the science of electrodynamics, now known as electromagnetism.
• VOLTAGE

  • Is the pressure from an electrical power source that pushes charged electrons (current) through a conducting loop, enabling them to do work.
  • Also known as the electromotive force (emf) or potential difference.
• Alessandro Volta

  • The unit volt was named after HIM, an Italian Physicist whose invention of the electric battery provided the first source of continuous current.
• RESISTANCE

  • A measure of the opposition to current flow in an electrical circuit.
  • Resistance is measured in ohms, symbolized by the Greek letter omega (Ω).
• According to Mazur (2021), all materials resist current flow to some degree. They fall into one of two broad categories:

  1. CONDUCTORS: materials that offer very little resistance where electrons can move easily.
  2. INSULATORS: materials that present high resistance and restrict the flow of electrons.