Introduction of Resistor

                  Introduction of Resistor

• Resistors are the basic component in an electronic circuit which is used to generate Voltage and Current in the circuit. 

• International Standards like IEC (International Electrical Commission) and ANSI(American National Standards Institute). 

• These standards are useful in having common resistor sizes, markings, values and measurement methods. 

• The standard resistor values are 10Ω,12Ω,15Ω,18Ω,22Ω,27 Ω,33 Ω,47 Ω,82 Ω 

• Color bands on the resistors are used to represent the resistance values on each of the resistor. 

• There are 4­band, 5­band and 6­band resistors. 

• From the figure, we can see that the first and the second band represent the numerical value of the resistor, the third band is a multiplier to the power of ten and the fourth band is the tolerance level. 

• Resistance calculation using Color Codes: 

1. First Band Second Band * Third Band 
2. Hence, the value of that resistor is Red: 2, Violet:7, 27, Brown: 10, 27 x10 = 270 Ohms, Gold: 5% tolerance. 
3. Resistance = 270Ω, 5% tolerance. 

• According to Ohm’s Law, Power is calculated as the product of Voltage and Resistance. 

• There are two types of resistor, they are

1. Fixed Resistor 
2. Variable Resistor