Band D on a resistor color code represents which property?

• A. First digit
• B. Tolerance
• C. Decimal multiplier
• D. Second digit

Answer: (B)

The last color band on a standard resistor tells you the tolerance—the allowed variation from the stated resistance value. In a typical four-band code, the first two bands give the digits of the resistance, the third band is the multiplier that scales those digits, and the fourth band is the tolerance. This tolerance tells you how precise the resistor is and how far the actual resistance can deviate from the printed value. For example, if that last band indicates 5% tolerance, a resistor labeled for a 330-ohm value could measure anywhere roughly from 313 to 347 ohms. The other bands establish the numeric value: the first two bands are the significant digits, and the third band sets the multiplier.