Question 1

Give the colour codes for the following values of resistors ( ignore tolerance):

A chart of resistor colour codes is shown below.


The answers for four-band colour codes are given below in bold.

The five-band version will also be shown.

Value Band 1 Band 2 Multiplier Comment
680 Ω blue grey brown 68 · 10
470 kΩ yellow violet yellow 47 · 10000
4M7 yellow violet yellow 47 · 100000. 4M7 is another way of writing 4.7 MΩ.
470 MΩ yellow violet violet 47 · 10000000
0.22 Ω red red silver 22 · 0.01
8.2 Ω grey red gold 82 · 0.1
180 Ω brown grey brown 18 · 10
150 kΩ brown green yellow 15 · 10000
8k2 grey red red 82 · 100. 8k2 is another way of writing 8.2 kΩ.
3.3 Ω orange orange gold 33 · 0.1


The answers for five-band colour codes are given below in bold.

For two significant digit resistances, the third band is always black, except for resistances less than 1 Ω. These have a first band that is black.

Value Band 1 Band 2  Band 3 Multiplier  Comment
680 Ω blue grey black black 680 · 1
470 kΩ yellow violet black orange 470 · 1000
4M7 yellow violet black yellow 470 · 10000. 4M7 is another way of writing 4.7 MΩ.
470 MΩ yellow violet black blue 470 · 1000000
0.22 Ω black red red silver 022 · 0.01
8.2 Ω grey red black silver 820 · 0.01
180 Ω brown grey black black 180 · 1
150 kΩ brown green black orange 150 · 1000
8k2 grey red black brown 820 · 10. 8k2 is another way of writing 8.2 kΩ.
3.3 Ω orange orange black silver 330 · 0.01


Question 2

State the nominal resistance values of the following colour coded resistors. Answers to be in the appropriate S.I. engineering units. e.g. 15 kΩ and not 15000Ω or 1.5 · 104 Ω.

A chart of resistor colour codes is shown below.


The table of answers is shown below.

The RKM code version is also used. This version uses R, K, or M as the "decimal point". It avoids using the ohm symbol Ω, which has been difficult to find in "ordinary" character sets. R means ohms, so 4R7 means 4.7 Ω. K means kΩ, so 47K means 47 kΩ. M means megohms, so 3M9 means 3.9 MΩ. The RKM code is used where the decimal point may be difficult to read.

Band 1 Band 2 Multiplier Value Value Comment
orange orange brown 330 Ω 330R 33 · 10
brown red yellow 120 kΩ 120K 12 · 10000
brown green brown 150 Ω 150R 15 · 10
orange white blue 39 MΩ 39M 39 · 1000000
brown black green 1 MΩ 1M 10 · 100000
brown grey orange 18 kΩ 18K 18 · 1000
green blue gold 5.6 Ω 5R6 56 · 0.1
blue grey silver 0.68 Ω R68 68 · 0.01. 0R68 would also be acceptable.
red violet green 2.7 MΩ 2M7 27 · 100000
yellow violet orange 47 kΩ 47K 47 · 1000
آخر تعديل: الخميس، 21 مايو 2020، 8:47 PM