## What is E12 series resistors?

The E12 series has 12 values for each multiple of ten; it is used for resistors with 10% tolerance. The values are 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82, then it continues 100, 120, 150 etc.

## How do you tell what size a resistor is?

Read the 3 or 4 numbers on the resistor. The first 2 or 3 represent the significant digits and the last indicates the number of 0s that should follow. For example, a resistor reading 1252 indicates a rating of 12,500 ohms or 1.25 kilo-ohms.

**What is resistor color code definition?**

The colour code used to denote the tolerance rating of a resistor is given as: Brown = 1%, Red = 2%, Gold = 5%, Silver = 10 % If resistor has no fourth tolerance band then the default tolerance would be at 20%.

**What is the difference between E12 and E24 and E6 resistors?**

As you can see the series E12 contains only every second value included in series E24 and series E6 only every second value included in series E12. A resistor of 150 W, for example, is thus available in all series (i.e. with every tolerance), but a resistor of say 5.6 kW is only available in series E12 and E24.

### What is the origin of the E12 and E24 series?

These older values were used to create the E6, E12, E24 series standard that was accepted in Paris in 1950 then published as IEC 63 in 1952. Eight of the E24 values do not match the following formula.

### What is the difference between E3 and E192 resistors?

Subdivisions of E3 to E192 ensure the maximum error will be divided in the order of 40%, 20%, 10%, 5%, 2%, 1%, 0.5%. Also, the E192 series is used for 0.25% and 0.1% tolerance resistors. Historically, the E series is split into two major groupings: E3, E6, E12, E24 — E3, E6, E12 are subsets of E24.

**What is the value of E12 for E6?**

E12 must preserve the values that were determined for E6, of course. The computed values for E12 are: E12 { 10 ⌊ 10 1 + 1 12 + 0.5 ⌋ = 12 15 ⌊ 10 1 + 3 12 + 0.5 ⌋ = 18 22 ⌊ 10 1 + 5 12 + 0.5 ⌋ = 26 33 ⌊ 10 1 + 7 12 + 0.5 ⌋ = 38 47 ⌊ 10 1 + 9 12 + 0.5 ⌋ = 56 68 ⌊ 10 1 + 11 12 + 0.5 ⌋ = 83