### device:

Resistor
* Most resistors are made of materials
  - change resistance
* Most resistors convert electrical energy
* Most resistors have three coloured bands close together at one end and one single band at the other
  - voltage
  - used in electronics today are carbon resistors
* Some resistors are part of bridges
  - cellphones
  - circuits
  - computers
  - laptops
  - processors
  - stereos
  - telephones
  - change in value when exposed to light
  - have energy
  - use graphite
* are basic components used to control the electrical current flow around a circuit board
  - common in electrical circuits
  - components that resist the flow of electrical current
  - devises that provide precise amounts of opposition or resistance to current flow
* are electrical components, which reduce the amount of voltage flowing through a circuit
  - devices
  - electronic components used extensively on the circuit boards of electronic equipment
  - in series if they carry necessarily the same current
  - metal film and oxide, with a few wirewounds
  - non-polarized which simply means it doesn t matter which end goes where
  - of a heat sink design for heat dissipation
  - one of the most widely used components in circuits
  - part of circuits
  - small
  - the simplest and most common circuit component
* are used to increase resistance in the circuit so it slows down the current
  - limit the current when the motor starts
* are very common in electric circuits
  - important in circuits
* are, as are capacitors, connected together in many ways.
* come in all different shapes and sizes.
* function like sponges in the water pipes i.e. they restrict the flow of electrons.
* generate heat.
* get hot when they are working because they exert control by converting power to heat.
* gives off heat.
* have different values of resistance
  - the tendency to hinder the flow of charge within electric circuits
* help solve the problem of voltage pressure by policing the processes.
* includes sections.
* is an electrical device
* limit current.
* offer a specified amount of resistance to current, and capacitors store electric charge.
* often look like tiny painted cans with two wires, one at each end.
* reduce the flow of a charge.
* restrict current flow through a circuit.
* take electrical energy and convert it to heat.
+ Electric current, Current in circuits
  * When current is flowing in a wire circuit, it accelerates when there is no resistance in the circuit. Resistors are used to increase resistance in the circuit so it slows down the current.
+ Resistor, Resistor Materials: Electronic components
  * There are many different types of resistors you can find. They are all made with a resistance material encased in a non-conductive material casing, such as plastic. Fixed resistors are usually made of carbon encased in  a plastic cylinder, with a connecting wire on either end. Most resistors used in electronics today are carbon resistors. Older resistors were made of a poorly conducting metal, in order to restrict the flow of electricity.
+ Traction motor, Transportation applications, Railroad: Motors :: Locomotives :: Vehicles :: Electricity
  * A series-wound DC motor has a low electrical resistance. When voltage is applied to the motor, it makes a strong magnetic field inside the motor. This produces a high amount of torque, so it is good for starting a train. If more current than needed is sent to the motor, there would be too much torque and the wheels would spin. If too much current is sent to the motor, it could damage the motor. Resistors are used to limit the current when the motor starts.