Resistor Color Code Flashcards: 4 Bands, 5 Bands & Tolerance
Practise 42 original resistor color-code prompts: decode and build conventional 4- and 5-band codes, calculate nominal tolerance intervals, and repair common errors.
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Read the band roles before doing the arithmetic. These 42 resistor color code flashcards use written color names to practise conventional four- and five-band resistor markings.
You’ll retrieve band roles and selected color values, decode codes into nominal resistance and tolerance, and build codes from an explicit band count, nominal value and tolerance. Reverse encoding is a separate card task because it needs recall in the other direction. Short calculations cover ohms, kiloohms and megaohms; nominal tolerance intervals; exact hypothetical boundary checks; and local repairs for wrong roles, zero digits, units and premature rounding.
All ten significant-digit colors and all conventional multipliers, including gold ×0.1 and silver ×0.01, appear across the set. Tolerance questions deliberately cover only brown ±1%, red ±2%, gold ±5% and silver ±10%. Other tolerance colors exist; this is not an exhaustive modern tolerance table. Every code-conversion prompt states the conventional band count and left-to-right order. One uncertainty task leaves direction unknown and asks whether a unique reading is possible.
The sequence introduces band roles and simple decoding before fractional multipliers, reverse encoding and interval work. Later cards mix those skills with error repair and limits of identification. Closely related variants are kept apart; the review scheduler handles long-term spacing. Every card carries the resistor-color-code tag.
You should be comfortable with decimal multiplication and percentages. Interval tasks use exact hypothetical numbers and the inclusive model R × (1 − t) to R × (1 + t), where t is the tolerance percentage divided by 100. They do not teach measurement procedures or include measurement uncertainty. A marked nominal value is not an exact measured value, and tolerance is not a probability distribution or a guarantee under every operating condition.
Text-only prompts make the tested mapping explicit without requiring color discrimination. Visual color identification, automatic reversal of every lookup, leading-zero encodings, special manufacturer schemes, six-band temperature coefficients, component availability and real electrical repair are excluded. Extra permutations were omitted when they added no distinct recall task. This evergreen Electronics deck is not aligned to an examination or curriculum.
Band roles and the tested color facts were checked against Vishay’s resistor color-code chart. SI unit conversions follow the BIPM prefix definitions. Numeric exercises, wording and organization were independently authored. No manufacturer chart artwork, source examples, competitor cards, article exercises or examination questions were copied or adapted.
AI tools assisted with drafting and the original decorative cover. The author manually read every final front and back and checked each applied answer; this does not claim learner testing or measured learning gains. The CC0 dedication covers original wording, examples, organization, metadata and generated cover to the extent applicable rights exist. Facts and cited materials retain their own status. This is independent, unofficial study practice, with no affiliation to or endorsement by Vishay or the other referenced organizations.
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Kadi namba 1
Swali
In a conventional 4-band resistor code, what does each band mean from left to right?
Jibu
Two significant digits, multiplier, tolerance.
Join the first two digits into one number, then multiply.
Kadi namba 2
Swali
In a conventional resistor code, what does a black band in a significant-digit position contribute?
Jibu
The digit 0.
Keep it in the number. A zero digit does not make the whole resistance zero.
Kadi namba 3
Swali
Conventional 4-band code, read left to right: orange–white–brown–gold. Nominal resistance and tolerance?
Jibu
390 Ω ±5%.
Orange–white gives 39; brown multiplies by 10. The final gold band gives ±5%.
Kadi namba 4
Swali
In the multiplier position of a conventional resistor code, what factor does black mean?
Jibu
×1.
A black multiplier leaves the significant-digit number unchanged.
Kadi namba 5
Swali
In a conventional 5-band resistor code, what does each band mean from left to right?
Jibu
Three significant digits, multiplier, tolerance.
The third band is another digit; the multiplier moves to the fourth position.
Kadi namba 6
Swali
Conventional 5-band code, read left to right: red–black–blue–black–brown. Nominal resistance and tolerance?
Jibu
206 Ω ±1%.
The digits are 2, 0, 6; the black multiplier is ×1. Final brown means ±1%.
Kadi namba 7
Swali
In the tolerance position of a conventional resistor code, what does gold mean?
Jibu
±5%.
This percentage describes a permitted deviation from the nominal resistance in the stated tolerance model.
Kadi namba 8
Swali
Can gold or silver be a significant digit in a conventional 4- or 5-band resistor code?
Jibu
No. Neither color represents a significant digit.
Gold and silver are used for multipliers or tolerances in this scheme.
Kadi namba 9
Swali
In the multiplier position of a conventional resistor code, what factor does gold mean?
Jibu
×0.1.
Divide the significant-digit number by 10.
Kadi namba 10
Swali
Conventional 5-band code, read left to right: brown–red–white–brown–gold. Nominal resistance and tolerance?
Jibu
1.29 kΩ ±5%.
The digits give 129; ×10 gives 1290 Ω. Final gold means ±5%.
Kadi namba 11
Swali
In the tolerance position of a conventional resistor code, what does red mean?
Jibu
±2%.
Read the band by its role: red can mean a digit, a multiplier, or a tolerance.
Kadi namba 12
Swali
Express 0.24 MΩ in kΩ.
Jibu
240 kΩ.
One megaohm is 1000 kiloohms: 0.24 × 1000 = 240.
Kadi namba 13
Swali
In the multiplier position of a conventional resistor code, what factor does silver mean?
Jibu
×0.01.
Divide the significant-digit number by 100.
Kadi namba 14
Swali
Conventional 4-band code, read left to right: violet–white–gold–silver. Nominal resistance and tolerance?
Jibu
7.9 Ω ±10%.
The digits give 79; gold multiplies by 0.1. Final silver means ±10%.
Kadi namba 15
Swali
A conventional 5-band resistor ends with a gold band. Does having five bands make its tolerance ±1%?
Jibu
No. Its final gold band means ±5%.
Band count changes the number of significant digits. It does not replace the tolerance band.
Kadi namba 16
Swali
Conventional 4-band code for 820 Ω ±2%, written left to right?
Jibu
Gray–red–brown–red.
82 × 10 = 820 Ω. The last red band specifies ±2%.
Kadi namba 17
Swali
In the tolerance position of a conventional resistor code, what does brown mean?
Jibu
±1%.
A brown tolerance band means one percent, not one ohm.
Kadi namba 18
Swali
Conventional 4-band code, read left to right: yellow–blue–silver–gold. Nominal resistance and tolerance?
Jibu
0.46 Ω ±5%.
The digits give 46; silver multiplies by 0.01. Final gold means ±5%.
Kadi namba 19
Swali
Conventional 5-band code for 64.2 kΩ ±1%, written left to right?
Jibu
Blue–yellow–red–red–brown.
642 × 100 = 64,200 Ω. Final brown specifies ±1%.
Kadi namba 20
Swali
For a nominal 1200 Ω resistor with ±5% tolerance, what is the nominal tolerance interval?
Jibu
1140–1260 Ω, including both endpoints.
5% of 1200 Ω is 60 Ω; subtract and add 60 Ω.
Kadi namba 21
Swali
In the multiplier position of a conventional resistor code, what factor does violet mean?
Jibu
×10,000,000.
That is ten million, or 10⁷.
Kadi namba 22
Swali
Conventional 4-band code, read left to right: blue–brown–yellow–brown. Nominal resistance and tolerance?
Jibu
610 kΩ ±1%.
61 × 10,000 = 610,000 Ω. Final brown means ±1%.
Kadi namba 23
Swali
Conventional 4-band code for 9.1 Ω ±10%, written left to right?
Jibu
White–brown–gold–silver.
91 × 0.1 = 9.1 Ω. Final silver specifies ±10%.
Kadi namba 24
Swali
For a nominal 75 Ω resistor with ±2% tolerance, what is the nominal tolerance interval?
Jibu
73.5–76.5 Ω, including both endpoints.
2% of 75 Ω is 1.5 Ω.
Kadi namba 25
Swali
In the multiplier position of a conventional resistor code, what factor does white mean?
Jibu
×1,000,000,000.
That is one billion, or 10⁹.
Kadi namba 26
Swali
Conventional 5-band code, read left to right: green–orange–black–green–red. Nominal resistance and tolerance?
Jibu
53 MΩ ±2%.
530 × 100,000 = 53,000,000 Ω. Final red means ±2%.
Kadi namba 27
Swali
Conventional 5-band code for 3.16 Ω ±1%, written left to right?
Jibu
Orange–brown–blue–silver–brown.
316 × 0.01 = 3.16 Ω. Final brown specifies ±1%.
Kadi namba 28
Swali
For a nominal 0.82 Ω resistor with ±5% tolerance, what is the nominal tolerance interval without rounding?
Jibu
0.779–0.861 Ω, including both endpoints.
The deviation is 0.82 × 0.05 = 0.041 Ω.
Kadi namba 29
Swali
In the multiplier position of a conventional resistor code, what factor does gray (grey) mean?
Jibu
×100,000,000.
That is one hundred million, or 10⁸.
Kadi namba 30
Swali
Conventional 4-band code, read left to right: brown–gray–blue–gold. Nominal resistance and tolerance?
Jibu
18 MΩ ±5%.
18 × 1,000,000 = 18,000,000 Ω. Final gold means ±5%.
Kadi namba 31
Swali
In the nominal interval model, a resistor is 250 Ω ±10%. Is an exact hypothetical value of 275 Ω inside, on a boundary, or outside?
Jibu
On the upper boundary, so it is included.
The interval is 225–275 Ω. This exact-number exercise ignores measurement uncertainty.
Kadi namba 32
Swali
Conventional 4-band code for 36 MΩ ±5%, written left to right?
Jibu
Orange–blue–blue–gold.
36 × 1,000,000 = 36 MΩ. Final gold specifies ±5%.
Kadi namba 33
Swali
For a nominal 2.4 kΩ resistor with ±1% tolerance, what is the nominal tolerance interval in kΩ?
Jibu
2.376–2.424 kΩ, including both endpoints.
The deviation is 0.024 kΩ. Keep the same unit throughout.
Kadi namba 34
Swali
Conventional 4-band code, read left to right: blue–black–orange–gold. A learner gets 0 Ω because black is 0. Correct the nominal value.
Jibu
60 kΩ.
Blue–black forms 60, then orange multiplies by 1000. The zero is a digit inside 60.
Kadi namba 35
Swali
In the nominal interval model, a resistor is 2000 Ω ±2%. Is an exact hypothetical value of 2041 Ω inside or outside?
Jibu
Outside.
The inclusive interval is 1960–2040 Ω. The hypothetical value is 1 Ω above the upper limit; measurement uncertainty is outside this exercise.
Kadi namba 36
Swali
Conventional 5-band code for 91.3 MΩ ±2%, written left to right?
Jibu
White–brown–orange–green–red.
913 × 100,000 = 91.3 MΩ. Final red specifies ±2%.
Kadi namba 37
Swali
Conventional 4-band code, read left to right: green–red–gold–brown. A learner treats gold as the tolerance. Give the correct nominal resistance and tolerance.
Jibu
5.2 Ω ±1%.
Gold is the third band, so it multiplies 52 by 0.1. Final brown supplies ±1%.
Kadi namba 38
Swali
A nominal 6.8 Ω resistor has ±1% tolerance. A learner rounds the deviation to 0.07 Ω before finding the limits. What is the unrounded interval?
Jibu
6.732–6.868 Ω.
Use the exact deviation, 6.8 × 0.01 = 0.068 Ω, before subtracting and adding.
Kadi namba 39
Swali
A conventional 5-band code is listed from one end: brown–green–black–brown–red. Reading direction and physical spacing are unknown. Is one nominal resistance uniquely determined?
Jibu
No. Both directions give valid readings.
As listed: 150 × 10 = 1500 Ω ±2%.
Reversed: red–brown–black–green–brown gives 210 × 100,000 = 21 MΩ ±1%. More orientation evidence is needed.
Kadi namba 40
Swali
A calculation gives 72,000 Ω. A learner writes 72 MΩ. Correct the unit conversion.
Jibu
72 kΩ, or 0.072 MΩ.
Divide ohms by 1000 for kiloohms, or by 1,000,000 for megaohms.
Kadi namba 41
Swali
Does a ±5% resistor tolerance mean there is a 95% probability that its resistance lies in the nominal interval?
Jibu
No. Tolerance is not a probability distribution.
It specifies a relative allowed deviation under the applicable specifications. The percentage alone does not give probabilities or cover every operating condition.
Kadi namba 42
Swali
Does seeing five bands on an unfamiliar real component prove that it uses the conventional 5-band resistor code?
Jibu
No. Confirm the component and marking scheme.
These cards assume conventional resistor markings. Special manufacturer schemes and six-band temperature-coefficient markings are outside this deck.
kadi 42
Resistor Color Code Flashcards: 4 Bands, 5 Bands & Tolerance
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