The color band on the most left is the 1st significant digit, followed by the 2nd digit and the multiplier. The fourth band is usually present as well and indicates the tolerance of the specified resistance. There is a handy resistor color code calculator available on the EE Undergraduate Lab homepage. Power rating of resistors In adition to the value and tolerance of a resistor, the power rating is another important characteristic. It tells how much power the resistor can dissipate before being damaged by overheating.
Lets look at an example.
Suppose you are using a 1k W resistor with a 0.25W power rating. The power rating depends on the physical size of the resistor, the larger the size, the larger the power rating will be. A microprocessor further manipulates the data before displaying the results. Schematic of the DMM as a DC voltage meter. An ideal voltmeter has an infinite input resistance so that it will not draw any current from the circuit under testing.