Carbon Resistor

• The carbon resistor is one of the most common types of composition resistor. The reason that they are so common is because they can be used for almost any general purpose and are relatively inexpensive. They are called carbon resistors because the resistor is composed or made up of carbon that has been finely ground. They can also be made out of a graphite material that resembles pencil lead. A powder made of clay is used to hold all the finely ground particles of carbon or graphite together. The higher levels of carbon in the resistor, the lower the resistance of the carbon resistor.
  
  

Film Resistors

• The three types of film resistors are metal, carbon, and metal oxide. The resistor is made from a ceramic rod and various types of metal. The most common metals used in the composition of these resistors are nickel and tin oxide. These types of resistors have a much higher tolerance than do composition type resistors. They react much more sensitively within the electronic components that they are used in.
  
  

Wirebound Resistor

• The wirebound resistor is similar in construction to the film type resistors. The wirebound resistor is constructed by wrapping a piece of metal wire around a piece of insulated ceramic. The wrapped wire resembles a helix. The most common type of wirebound resistor is the power wirebound resistor. They are used most commonly because of the fact that they are able to handle higher temperatures and a higher rate of power. These resistors are typically used in DC motors, space heaters and cabinet heaters.
  
  

Color Coding

• All resistors are color coded so that they can be easily read. The color coding is used to indicate simply by sight what the resistor is capable of. Bigger resistors have the tolerance, value of resistance, and the rating of wattage printed on the side. However, smaller resistors do this by color coding. The different colors on painted onto the resistor tell electricians the resistor's capabilities.