Color code practice: What are the correct 4-band color stripes for a 4,700 Ω resistor with ±10% tolerance?
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Ayellow, violet, red, gold
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Byellow, violet, orange, gold
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Cyellow, violet, red, silver
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Dorange, violet, red, silver
Answer
Correct Answer: yellow, violet, red, silver
Explanation
Introduction / Context:Reading resistor color codes quickly is a vital technician skill. For a 4-band resistor, the first two bands are significant digits, the third is the power-of-ten multiplier, and the fourth is the tolerance. Here we map a specified resistance and tolerance back to its color stripes.
Given Data / Assumptions:
- Target resistance: 4,700 Ω (i.e., 4.7 kΩ).
- Tolerance: ±10%.
- Standard color-digit mapping applies.
Concept / Approach:Express the value in two significant digits times a power of ten: 4,700 Ω = 47 × 10^2. Then map 4 → yellow, 7 → violet, multiplier 10^2 → red, tolerance ±10% → silver.
Step-by-Step Solution:
Write 4,700 as 47 × 10^2.First digit 4 → yellow; second digit 7 → violet.Multiplier 10^2 → red; tolerance ±10% → silver.Complete code: yellow, violet, red, silver.Verification / Alternative check:If tolerance were ±5%, the last band would be gold, not silver. If the value were 47 kΩ (47 × 10^3), the third band would be orange (10^3), illustrating the importance of the correct multiplier.
Why Other Options Are Wrong:
- Yellow, violet, red, gold: Gold is ±5%, not ±10%.
- Yellow, violet, orange, gold: Multiplier 10^3 and tolerance ±5%—this encodes 47 kΩ ±5%, not 4.7 kΩ ±10%.
- Orange, violet, red, silver: First digit orange is 3, not 4; would encode 3.7 kΩ ±10% if the rest matched.
Common Pitfalls:
- Mismatching multiplier color (red vs orange) leading to decade errors.
- Confusing gold and silver tolerances.
Final Answer:yellow, violet, red, silver