Colour Code of Carbon Resistors: How to Read the Bands
Physics · Current Electricity · NEET
A carbon resistor's value is printed as coloured rings: the first two bands give the two significant digits, the third band is the power-of-ten multiplier, and the fourth band is the tolerance (Gold = 5%, Silver = 10%). So R = (first digit)(second digit) x 10^(third band) ohm. Memory hook: "BB ROY of Great Britain has a Very Good Wife" gives Black 0, Brown 1, Red 2, Orange 3, Yellow 4, Green 5, Blue 6, Violet 7, Grey 8, White 9.
A 4-band carbon resistor: first two bands (Yellow 4, Violet 7) are the digits 47, the third band (Orange) is the multiplier x10^3, and the last band (Gold) gives the tolerance +/-5%, so R = 47 x 10^3 = 47 kilo-ohm.
Your doubts, answered
What does each of the four bands mean?
Band 1 = first significant digit. Band 2 = second significant digit. Band 3 = multiplier (the power of ten you multiply by). Band 4 = tolerance (how much the real value can differ). Example: Yellow-Violet-Orange-Gold = 4, 7, x10^3, +/-5% = 47 x 10^3 = 47000 ohm = 47 kilo-ohm at +/-5%.
How do I remember the colour-to-number order?
Use the sentence 'BB ROY of Great Britain has a Very Good Wife'. Take the first letter of each word: B-B-R-O-Y-G-B-V-G-W. This maps to Black 0, Brown 1, Red 2, Orange 3, Yellow 4, Green 5, Blue 6, Violet 7, Grey 8, White 9. NEET questions expect you to recall this order fast.
Which colour is the tolerance band, Gold or Silver?
Gold as the last band means +/-5% tolerance and Silver means +/-10%. If there is no fourth band at all, the tolerance is +/-20%. Do not confuse tolerance with the multiplier: Gold and Silver can also act as multipliers (x10^-1 and x10^-2) but only when they appear as the third band, not the last one.
How do I find the colour of the third band from a given resistance?
Write the resistance in the form (two digits) x 10^n. The power n is the multiplier, and its colour is the third band. Example: 22000 ohm = 22 x 10^3, so the multiplier is 10^3, and 3 = Orange. So the third band is Orange.
Why does the order of the bands matter?
The bands are read from the end that has bands closer together, toward the tolerance band. Yellow-Violet-Orange means 47 x 10^3 = 47 kilo-ohm, but Violet-Yellow-Orange would mean 74 x 10^3 = 74 kilo-ohm. Reversing the first two digits gives a completely different resistor, so NEET options often swap them as a trap.
⚠️ The NEET trap ✗ Reading Gold or Silver as a multiplier when it is actually the last (tolerance) band, or swapping the first two digits. ✓ The last band is always tolerance: Gold = +/-5%, Silver = +/-10%. The first two bands, in the order they are read, are the two significant digits; the third band is the power of ten. 🧠 Last band = tolerance, not a digit. Read digits in order: Yellow-Violet is 47, never 74.
Real NEET questions
NEET 2018
A carbon resistor of (47 +/- 4.7) kilo-ohm is to be marked with rings of different colours for its identification. The colour code sequence will be:
A · Yellow-Green-Violet-Gold
B · Yellow-Violet-Orange-Silver ✓
C · Violet-Yellow-Orange-Silver
D · Green-Orange-Violet-Gold
Solution: Step 1: Write the value. 47 kilo-ohm = 47 x 10^3 ohm. Step 2: Digits. First digit 4 = Yellow, second digit 7 = Violet. Step 3: Multiplier. x10^3, and 3 = Orange (third band). Step 4: Tolerance. 4.7 / 47 = 0.10 = +/-10%, and 10% = Silver. Sequence = Yellow-Violet-Orange-Silver, option B.
NEET 2020
The colour code of a resistance is given (Yellow, Violet, Brown, Gold). The values of resistance and tolerance, respectively, are:
A · 4.7 kilo-ohm, 5%
B · 470 ohm, 5% ✓
C · 470 kilo-ohm, 5%
D · 47 kilo-ohm, 10%
Solution: Step 1: Digits. Yellow = 4, Violet = 7, so the two digits give 47. Step 2: Multiplier. Brown = 1, so multiplier = x10^1. R = 47 x 10^1 = 470 ohm. Step 3: Tolerance. Gold = +/-5%. So R = 470 ohm at +/-5%, option B.
NEET 2023
Resistance of a carbon resistor from colour codes is (22000 +/- 5%) ohm. The colour of the third band must be:
A · Red
B · Green
C · Orange ✓
D · Yellow
Solution: Step 1: Standard form. 22000 = 22 x 10^3. Step 2: Digits. 2, 2 = Red, Red (first two bands). Step 3: Multiplier. The third band is the multiplier x10^3, and 3 = Orange. Step 4: Check tolerance. +/-5% = Gold (fourth band). So the third band is Orange, option C.
Solved Current Electricity NEET PYQs
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Use 'BB ROY of Great Britain has a Very Good Wife': Black 0, Brown 1, Red 2, Orange 3, Yellow 4, Green 5, Blue 6, Violet 7, Grey 8, White 9. First two bands are digits, third is the power of ten, fourth is tolerance.
What is the difference between Gold and Silver bands?
As the last (tolerance) band, Gold means +/-5% and Silver means +/-10%. No fourth band means +/-20%. As a third band (multiplier) Gold is x10^-1 and Silver is x10^-2, but that is rare in NEET.
What does Yellow-Violet-Orange-Gold mean?
Yellow = 4, Violet = 7, Orange = x10^3, Gold = +/-5%. So R = 47 x 10^3 = 47000 ohm = 47 kilo-ohm at +/-5% tolerance.
How many bands does a carbon resistor usually have for NEET?
NEET uses the 4-band code: two digit bands, one multiplier band, one tolerance band. You only need this 4-band system for the exam.
Is the colour code still in the NCERT syllabus?
The rationalised NCERT Current Electricity chapter no longer prints the colour-code table, but NEET has asked it in 2018, 2020, and 2023, so you must still learn it.
