Module 2 Electric Potential and Electric Current

• Voltage - It is the electric potential difference between any points in a circuit.
• SI unit of voltage is volt (V).
• Voltage = cℎange in electric potential
• Electric potential difference is the amount of work done to carry a unit charge from one point to another in an electric field.
• SI unit of electric potential difference is volt (V).
• Work is the product of force and displacement.SI unit of work is Joules (J).
• WORK-ENERGY THEOREM

  The principle of work and kinetic energy states that the work done by the sum of all forces acting on a particle equals the change in the kinetic energy of the particle.  
• The mechanical energy is the sum of kinetic and potential energies.
• LAW OF CONSERVATION OF ENERGY

  This law states that the final energies is equal to initial energies.
• The electric potential is defined as electric potential energy per unit charge.Electric potential is represented with the symbol  V.
• VOLT

  The unit of electric potential and electric potential difference is Joules/Coulomb (J/C) which is also equal to volt (V).
• An Italian physicist, Alessandro Volta, invented the first electric battery namely voltaic pile. 
• Voltaic pile is a battery invented by Volta. In this battery, layers of zinc, brine-soaked pasteboard or cloth and silver are being stacked up.
• The voltaic pile is the first device that emit steady and lasting current.
• ENERGY - The SI unit of energy is Joules (J). But a joule is a very large unit in dealing with the energies of electrons, atoms, or molecules.
• Instead of using joule, another unit is to be used: electron volt (eV)
• ELECTRON VOLT (eV) - One electron volt is defined as the energy acquired by a particle carrying a charge of whose magnitude equals that on the electron (q=e) as a result of moving through potential difference of 1V.
• 1 eV = (1.602 x 10^-19 C)(1.0 V) Therefore : 1 eV = 1.602 x 10^-19 J
• STATIC ELECTRICITY

  Ø Electricity is produced when electric charges are at rest.

  Ø Charges are located on the surface of the material.
• DYNAMIC ELECTRICITY

  Ø Electricity is produced when electric charges are at motion.

  Ø Charges are moving from one atom to another.
• Chemical  --> Electrical = Battery
• Electrical --> Chemical = Electrolysis of water
• Mechanical --> Electrical = Generator
• Electrical --> Mechanical = Motor
• Light --> Electrical = Solar cell
• Electrical  --> Light = Light Bulb
• Heat --> Electrical = Thermoelectric Gen
• Electrical --> Heat = Toaster
• Sound --> Electrical = Microphone
• Electrical --> Sound = Speaker
• A battery produces electricity by transforming chemical energy into electrical energy.
• A simple battery contains two plates or rods made of dissimilar metals called electrodes.
• These electrodes are  immersed in a solution such as dilute acid, called electrolytes.
• A single device with electrodes immersed in a electrolytes is called electric cell.
• Series of electric cell connected together is called battery. And its purpose is to produce potential difference.
• Electric circuit means that a continuous conducting path is connected between the terminals of a battery.
• A terminal is the part of the electrode outside of the electrolytes.
• An  electric current is defined as the net amount of charge that passes through the wire’s cross section at any point per unit time.
• SI unit of current is Ampere (A).
• If electric potential is measured in joules per coulomb or volt.