What does a gold band at the end of a resistor's color bands indicate?

The presence of a gold band at the end of a resistor's color bands indicates a tolerance of 5%. Tolerance refers to the degree of variation that is acceptable in the resistor's resistance value. In electronic components, tolerances are critical because they determine how closely the actual resistance can match the intended resistance.

The gold band specifically indicates that the resistor can have a variation of ±5% from its stated value. This means if a resistor is rated at 100 ohms, it could actually measure anywhere from 95 ohms to 105 ohms and still fall within the acceptable performance range. This level of tolerance is commonly used in many applications where precision is important, but not to the extent where tighter tolerances are necessary.

In comparison, other tolerance levels indicated by the color bands include silver for 10% and other colors for different percentages, and a band of brown for 1%. Understanding these tolerances helps in selecting the right resistor for a particular circuit requirement, ensuring reliability and performance in electronic designs.