Resistor color coding (4-band) practice: What is the correct color code for a 220 Ω, 5% tolerance resistor?

Introduction / Context:Color coding allows quick identification of resistor values without reading tiny printed numbers. The standard 4-band code uses two significant digits, a multiplier, and a tolerance band.

Given Data / Assumptions:

• Target resistance: 220 ohms.
• Tolerance: 5 percent.
• Standard 4-band E12 or E24 series coding.

Concept / Approach:Digit colors: Black 0, Brown 1, Red 2, Orange 3, Yellow 4, Green 5, Blue 6, Violet 7, Gray 8, White 9. Multiplier band is 10^n with the same color mapping. Gold indicates 5 percent tolerance, silver indicates 10 percent.

Step-by-Step Solution:Write 220 in significant-digit and multiplier form: 22 * 10^1.First band (2): Red.Second band (2): Red.Multiplier (10^1): Brown.Tolerance (5%): Gold.

Verification / Alternative check:A quick check: Red-Red-Black would be 22 * 10^0 = 22 Ω, which is not correct. Red-Red-Brown yields 220 Ω, matching the requirement, and gold is the correct 5 percent tolerance band.

Why Other Options Are Wrong:

• Orange, Orange, Black, Gold: 33 * 10^0 = 33 Ω.
• Red, Red, Black, Gold: 22 Ω, not 220 Ω.
• Red, Red, Brown, Silver: 220 Ω but 10 percent tolerance, not the specified 5 percent.
• Brown, Black, Brown, Gold: 10 * 10^1 = 100 Ω, incorrect value.

Common Pitfalls:Mixing up the multiplier band with a third significant digit and confusing tolerance colors gold versus silver.

Final Answer:Red, Red, Brown, Gold