What is Resistor?

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What is resistor? – Resistors are one of the passive components that function as an inhibitor of electricity current in electrical circuits. What is the meaning of passive component? Passive component is component does not require an energy source for active from other components to be able to utilize electric current.

resistor is electronics component

Resistors are basic components of electronics that are used to limit the amount of current flowing in a series. As the name implies resistors are resistive and generally made of carbon. From Ohms law it is known that resistance is inversely proportional to the amount of current flowing through it.

The unit of resistance of a resistor is called Ohm or symbolized by the symbol Ω (Omega). To declare resistance should be included in the limits of its power capability. Various types of resistors are made from different materials with different properties.

Another specification that needs to be considered in choosing a resitor for a design other than the large resistance is the wattage. Because the resistor works by electric current, there will be a power dissipation in the form of heat of W = I 2 R watts.

The greater the physical size of a resistor can show the greater the ability of the resistor’s power dissipation. Generally in the market there are sizes of 1/8, 1/4, 1, 2, 5, 10 and 20 watts.
Resistors that have a power dissipation of 5, 10 and 20 watts are generally rectangular-shaped cubic white shapes, but there are also cylindrical shapes. But usually for this jumbo size resistor the resistance value is printed directly

In the body, for example 100Ω5W. Resistors in theory and practice are written with symbolic letters R. Judging from the physical size of a resistor with one another does not mean the same value of the resistance. The resistor resistance value is called resistance.


This resistor is the most basic electronic component that must be Learn. Because the use of this component in electronics cannot be removed. Almost all need resistors. The unit of this resistor is “Ohm” Ω. In Figure below, there are two most commonly used  symbols.

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resistor symbol

A symbol such as a jag or zigzag is a symbol of American and Japanese standard, while a square is a European standard.


How it work

Resistors of the word “Resist” which means defended, rejected, or blocked. What is blocked? The answer is electric current. In short, we can analogize that an electric current like a flow of water, while a resistor is a water pipe.

When water flows in a clean pipe, the amount of come in is the same as the comes out. However, if the pipe is dirty, there is a lot of moss or clumps of land, so the amount of come in is not the same as coming out. Well, the pipe is also called the Resist component, because it has retained the flow of water with moss and soil clumps.

To limit their ability to withstand electric current, depending on the value of resistance. The greater the resistance value, the greater the electric current resist, and vice versa.

Resistors are divided into two types, with fixed resistance values ​​and resistors with changeable resistance values. A resistor with a fixed value is called a Fixed Resistor, while resistance value can be changed called a Variable Resistor.



Fixed resistors are very many derivatives or types depending on the of the resistor itself, but in general based on the material of manufacture, currently divided into four large groups, namely:

  • Carbon Resistor (made with carbon material)
  • Resistor Film (resistors made with metal oxide materials are usually low power)
  • Wire-wound resistors (resistors made with typically high-power winding wire)
  • Semiconductor resistors (resistors made with semiconductor materials).

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