• Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge.


  • Current measures motion of charge per second past a point


  • Voltage measures energy per coulomb


  • Resistance is the opposition that a substance offers to the flow of electric current.
  • When an electric current of one ampere passes through a component across which a potential difference (voltage) of one volt exists, then the resistance of that component is one ohm.

Ohm’s Law

  • Ohm’s law states that the current through a conductor between two points is directly proportional to the voltage across the two points.


  • A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses.


  • Resistivity is a measure of the resistance of a given size of a specific material to electrical conduction. Resistivity may also be referred to as the specific electrical resistance, or volume resistivity, although these terms are less widely used.

Parallel Plate Capacitors

  • The parallel plate capacitor is the simplest form of capacitor. It can be constructed using two metal or metallised foil plates at a distance parallel to each other, with its capacitance value in Farads, being fixed by the surface area of the conductive plates and the distance of separation between them. Altering any two of these values alters the value of its capacitance and this forms the basis of operation of the variable capacitors.


  • Capacitance is the ratio of the change in an electric charge in a system to the corresponding change in its electric potential. There are two closely related notions of capacitance: self capacitance and mutual capacitance. Any object that can be electrically charged exhibits self capacitance.


  • A capacitor is a device that stores electrical energy in an electric field. It is a passive electronic component with two terminals. The effect of a capacitor is known as capacitance