A resistor with a gold band as the fourth one has a tolerance percentage of what?

A resistor that has a gold band as the fourth band indicates a tolerance of 5%. Tolerance in resistors tells us how much the actual resistance can vary from the stated value. For example, if a resistor is rated at 100 ohms with a 5% tolerance, the resistance can actually range from 95 ohms to 105 ohms.

In the context of resistor color codes, the first two bands indicate significant figures of the resistance value, the third band represents the multiplier, and the fourth band specifies the tolerance. Gold is specifically designated for a 5% tolerance level, which is commonly used in various electronic applications where a moderate degree of resistance deviation is acceptable.

Other bands signify different tolerance levels: silver indicates 10%, while no band would indicate a tolerance of 20%. Hence, the presence of the gold band clearly establishes the tolerance percentage at 5%.