Resistor color code interpretation – brown–black–red–gold A carbon film resistor shows color bands: brown (1), black (0), red (multiplier 10^2), gold (tolerance). What is the resistance value including tolerance?
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A100 Ω
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B1000 Ω
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C1000 Ω ± 5%
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D1000 Ω ± 10%
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E10 kΩ ± 5%
Answer
Correct Answer: 1000 Ω ± 5%
Explanation
Introduction / Context:Color bands on resistors encode their nominal value and tolerance. Mastering the code enables quick identification in labs and field work without measuring each part. The standard four-band system uses two significant digits, a multiplier, and a tolerance band.
Given Data / Assumptions:
- Band 1 (brown) = 1, Band 2 (black) = 0.
- Multiplier (red) = 10^2.
- Tolerance (gold) = ±5%.
- Assume standard E24 series conventions for four-band resistors.
Concept / Approach:
The first two bands form the significant figures; the third band scales them by the power of ten multiplier; the fourth band gives tolerance. Combining these yields the nominal resistance and permissible variation range.
Step-by-Step Solution:
Significant digits: 1 (brown), 0 (black) → '10'.Multiplier: red → × 10^2 = × 100.Nominal resistance: 10 × 100 = 1000 Ω.Tolerance: gold → ±5%.Verification / Alternative check:
Cross-check with standard tables: brown-black-red equals 1.0 kΩ; gold tolerance equals ±5% → range 950 Ω to 1050 Ω.
Why Other Options Are Wrong:
100 Ω ignores the multiplier; 1000 Ω without tolerance omits key spec; ±10% corresponds to silver, not gold; 10 kΩ ± 5% would require orange or a different pattern.
Common Pitfalls:
Reading the bands in reverse (especially with five-band parts), confusing gold and silver meanings, or misplacing the multiplier band.
Final Answer:
1000 Ω ± 5%