What is a 100 Ohm Resistor? 100 Ohm Resistor Color Code

The 100 ohm resistor holds a prominent place in electronic components. Its frequent use makes it an ideal candidate for understanding the resistor color code, facilitating easy recognition in various projects alongside other commonly employed resistors. The color code associated with the 100 ohm resistor enables swift identification of its resistance value and tolerance. This article will guide you on deciphering 4-band, 5-band, and 6-band configurations for 100 ohm resistors.

What is a 100 Ohm Resistor?

Resistors find common application in electrical systems, where their primary function involves regulating the passage of electrical current. Typically compact, these components feature wire leads extending from various directions. Operating as distinctive elements within circuits, resistors are crafted to impart specific electrical resistance values. A resistor rated at 100 ohms is an electrical device employed to moderate current fine-tune signal magnitudes and partition voltages. Constructed from a substance inherently impeding the flow of electricity, often a carbon-based compound, these resistors play a crucial role in controlling current within electronic circuits and safeguarding other components from potential overload. Furthermore, they serve to calibrate electronic elements and contribute to voltage division circuits.

Who Makes a 100 Ohm Resistor?

Various manufacturers, including prominent industry names such as Vishay, Bourns, and Panasonic, produce 100 ohm resistors. These resistors are offered through-hole and surface mount configurations, with diverse wattage ratings, temperature coefficients, and tolerances. Depending on the specific manufacturer, 100 ohm resistors may also feature different lead arrangements, such as axial or radial.

When choosing a 100 ohm resistor, it is crucial to consider factors like the temperature coefficient, power rating, and component tolerance. This ensures that the resistor can effectively manage the anticipated current and voltage levels. Additionally, the resistor's form factor should be considered, as it dictates the component's size and shape, determining its compatibility with the designated space on the circuit board. Given the array of manufacturers and options available, finding the ideal 100 ohm resistor for any application is straightforward.

100 Ohm Resistor Color Code

Recognizing that all four bands don't signify the resistance in Ohms is crucial. The initial three bands convey the resistor's nominal value as 100 Ohms, while the fourth band indicates the resistor's tolerance.

Every resistor has a tolerance, implying that the actual value may not be 100 Ohms. Resistors of superior quality generally exhibit more accurate tolerances.

100 Ohm Resistor Color Bands

Begin by locating the last band, distinctively set apart from the others by a small gap. Typically gold or silver, this band is often the easiest to discern and reveals the resistor's tolerance.

Once the 4th band is identified, shift attention to the bands on the opposing side of the resistor. The initial two bands provide a foundational value, necessitating multiplication by the multiplier to ascertain the complete resistance value.

The third band serves as the multiplier. Execute the multiplication of the value indicated by the first two bands with the multiplier to unveil the comprehensive resistor value.

Further elaboration on this procedure is provided in the subsequent sections.

100 Ohm Resistor Color Chart

Band Number	Function	Color	Value
1	1st Digit	Brown	1
2	2nd Digit	Black	0
3	Multiplier	Yellow	x 10
4	Tolerance	Gold (or silver)	± 5% (± 10% for silver)
Total Value:                                                                                              100 ± 5% Ω

To determine the color code of a 100 ohm resistor, refer to the resistor color chart. The image below illustrates the color code for a 100R 4-band resistor:

The color code for the four bands of a 100 Ohm resistor is brown, black, brown, gold.

Calculating the 4-band 100 ohm resistor color code:

• 1st band = Brown = 1 (1st digit)

• 2nd band = Black = 0 (2nd digit)

• 3rd band = Brown = 1 (multiplier) = 10^1 = 10

• 4th band = Gold = ±5% (tolerance)

Thus, 100 × 1 ± 5% → 100 ohms → 100 Ω

The tolerance is → 5% of 100 → 5 Ω

Theoretically, the value of a 100 Ω resistor ranges between 95 Ω to 105 Ω.

Description:

 

Refer to the chart below to decode the color bands and corresponding decimals. For a 100-ohm resistor, the 1st digit is '1', so locate the color with a value of 1 in the chart (brown). The 2nd digit is '0', so find the color with a value of 0 (black). The 3rd digit, '0' (but value 10^1 = 10), is the multiplier '1', so find the color with a value of 1 (brown).

The last band in 4 and 5-band resistors indicates the tolerance value. In this case, Gold signifies a 5% tolerance. Silver indicates 10% tolerance, and Brown indicates 2%. If the 4th band is absent, it should be considered as a 20% tolerance.

Illustration depicting the color code for a 100 ohm 5-band resistor:

The color code for the 100R 5-band resistor is brown, black, black, black, gold, and it is represented as:

• 1st band = Brown = 1 (1st digit)

• 2nd band = Black = 0 (2nd digit)

• 3rd band = Black = 0 (3rd digit)

• 4th band = Black = 0 (multiplier) = 10^0 = 1

• 5th band = Gold = ±5% (tolerance)

Description:

For a 100-ohm 5-band resistor,

• The 1st digit is '1', so refer to the chart for the color with the value 1, and that's your 1st color (brown).

• The 2nd digit is '0', so find the color with the value 0, which becomes the 2nd band color (black).

• The 3rd digit is '0', so look for the color with the value 0, which becomes the 3rd band color (black).

• Now, the 4th digit is the multiplier value (10^0 = 1), which is zero; hence, the 4th band will be black.

How to Read the 100 Ohm Resistor Color Code

Resistor color codes typically include digits, a multiplier, and a tolerance value, while six-band resistors also introduce a temperature coefficient.

Starting with four-band resistors is the most straightforward approach. Once you grasp the four-band system, comprehending the color coding of five and six-band resistors becomes relatively straightforward.

Let's review the resistor color code table and the method for determining values:

Resistors, prevalent in various values and power ratings, are commonly utilized in circuits. The color-coded bands on lower-power resistors convey information about resistance and tolerance, as depicted in the figures above.

In the case of the 100-ohm resistor illustrated above, the bands are clustered toward one end of the resistor. The color band closest to one end represents the 1st digit of the value. The subsequent band is the second digit, the third is a third digit (for 5-band resistors), the next band is the multiplier, and the last band determines the tolerance value.

The associated values for the diverse band colors are detailed:

For instance, a resistor with yellow, violet, orange, and gold bands corresponds to a value of 47 × 1000 ± 5% Ohms.

Size of Resistors

Resistors are available in variable configurations, allowing their values to be adjusted by various means. A variable resistor with two pins is termed a rheostat. The more prevalent and adaptable type features three pins and is known as a potentiometer, commonly referred to as a "pot."

It is essential to choose the appropriate power rating for a resistor when needed. Their size denotes the power rating of standard resistors. Common wattage values include 1/8, 1/4, 1/2, 1, 2, 5 watts, etc.

The 4 Band 100 Ohm Resistor

Each band on the resistor serves a distinct purpose:

Band One – 1st Digit: Representing the initial digit of the resistance value, the first band, colored brown, corresponds to the value 1.

Band Two – 2nd Digit: Signifying the second digit of the resistance value, the black second band complements the first digit from band one, resulting in the digit 10.

Band Three – Multiplier: This band multiplies the combined digits by a value determined by its color. The actual multiplier is 10^n, where n is the numerical value assigned to the band color. In this instance, the third band, brown, corresponds to the number 1, making the multiplier 10^1 = 10.

Consequently, the total resistance value determined by the colors is 10 (from digits) × 10^1 (from multiplier) Ω = 100Ω.

Band Four – Tolerance: Indicating the tolerance value for the resistor, common values include 5% (depicted by a gold band) and 10% (represented by a silver band). Using a gold band in this example yields a tolerance of 5%.

Hence, the overall resistance is: 100Ω ± 5% Ω.

This signifies that the true resistance value may range from 95 Ω to 105 Ω. If the fourth band is silver, indicating a 10% tolerance, the total resistance becomes 100Ω ± 10% Ω, with the actual resistance expected to fall between 90 Ω and 100 Ω.

A multimeter proves helpful for verifying resistors, offering a reliable method to determine their resistance. It's essential to consider practical safety guidelines while using multimeters. In 6-band resistors, the last band provides information on temperature dependence (further details below).

100 ohm resistors can be recognized by the resistor color code of Brown-Black-Brown-Gold, and for five-band resistors, it is Brown-Black-Black-Black-Gold. Suppose you want to measure the color code of other resistors besides the 100 ohm resistor colour code. In that case, you can use the Resistor Color Code Calculator, which will help you identify the resistors' colour code accurately and quickly.

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4-Band vs. 5-Band vs. 6-Band 100 Ohm Resistor Color Code

You may come across resistors with 5 or even 6 bands.

Reading 5 or 6 band resistors becomes straightforward if you are already familiar with using four-band resistor color coding.

5 Band 10K Resistor Color Code

In the case of 100 Ohm resistors featuring five bands, the initial three bands will be brown, black, and black (signifying 100), while the fourth band will be black, denoting a multiplier of x1.

Band Number	Function	Color	Value
1	1st Digit	Brown	1
2	2nd Digit	Black	0
3	3rd DigitBlack	Black	0
4	Multiplier	Black	x 1
5	Tolerance	Gold (or silver)	± 5% (± 10%)
Total Value:                                                                                               100 ± 5% Ω

4-Band vs. 5-Band vs. 6-Band 100 Resistor Color Code Table

4 Band vs. 5 Band 100 Ohm Resistor

Resistors with four bands allocate two bands for the value, one for the multiplier, and one for the tolerance.

In contrast, five-band resistors introduce an additional band for the value. Consequently, they feature three bands for the value, one for the multiplier, and one for the tolerance. Scrutinizing the resistor remains consistent: initiate the examination with the 5th band, identify a slight gap between the fourth and fifth bands, and designate the tolerance. Then, revert to the first four bands to compute the resistance value.

For a 100-ohm resistor with five bands, the expected sequence is brown (1), black (0), black (0), black (x1), and gold or silver (± 5% or 10%).

6 Band 100 Ohm Resistor

Band Number	Function	Color	Value
1	1st Digit	Brown	1
2	2nd Digit	Black	0
3	3rd DigitBlack	Black	0
4	Multiplier	Black	x 1
5	Tolerance	Gold (or silver)	± 5%
6	Temp. Coefficient	Any	See Chart Below
Total Value:                                                                                                      100 ± 5% Ω

Six-band resistors mirror their five-band counterparts, differing only in adding an extra band that signifies the temperature coefficient — specifically, the extent to which resistance will vary with temperature.

In this scenario, the last two bands (the fifth and sixth bands) ought to be in close proximity, featuring a discernible gap between the fourth and fifth bands.

Applications of 100 Ohm Resistor

Frequently employed in breadboards and various prototyping scenarios, these 100 ohm resistors serve adeptly as pull-ups, pull-downs, and current limiters. The stout-lead variants of these resistors seamlessly integrate into breadboards, exhibiting minimal displacement. Hence, incorporating them into your upcoming project should pose minimal challenges or concerns.

Breadboard Prototyping:

In electronic breadboard prototyping, 100 ohm resistors are commonly enlisted for their adaptability, proving well-suited for various applications within these experimental setups.

Pull-Up Resistors:

Functioning as pull-up resistors, these components are frequently incorporated into circuits to establish a defined logic level when a signal line is either unconnected or in a high-impedance state. This is indispensable for maintaining stability in digital circuits.

Pull-Down Resistors:

Serving as pull-down resistors, they are pivotal in ensuring a predetermined low logic level when a signal line is either unconnected or not actively driven. This holds particular significance in digital circuits to prevent erratic inputs.

Current Limiters:

Within diverse electronic circuits, especially those involving LEDs or delicate components, 100 ohm resistors can fulfill the role of current limiters. Their function involves managing the flow of current, averting components from drawing excessive current and ensuring proper functionality.

How to Make a 100 Ohm Resistor?

Creating a 100 ohm resistor necessitates a fundamental grasp of resistor construction and color coding. Begin by acquiring a resistor with the desired resistance value, readily accessible in the market. The color code for a 100 ohm resistor entails brown, black, and brown, where each color corresponds to a specific digit. Brown denotes 1, black signifies 0, and brown serves as a multiplier of 10. Assemble the resistor by linking the leads to the designated points on the resistor body. Maintaining precision in the color-coding process is paramount, as any deviation may yield an inaccurate resistance value. Once assembled, the 100-ohm resistor can seamlessly integrate into electronic circuits, effectively regulating current flow and voltage levels.

An alternative approach involves winding a length of slender nichrome wire around a ceramic insulator. Alternatively, you can acquire an adjustable pre-wound resistor and configure it to achieve 100 ohms. The process typically commences with a resistive material possessing a known resistivity, such as carbon composition or metal film.

Final Words

When choosing a 100 ohm resistor for a specific use, it is crucial to consider factors like the wattage rating, tolerance, and temperature coefficient. The wattage rating signifies the maximum power the resistor can handle without undergoing overheating, while the tolerance denotes the utmost permissible variation in resistance over time. The temperature coefficient indicates the extent of resistance variation with temperature, a significant consideration in applications exposed to extreme temperature conditions.

In general, 100 ohm resistors are versatile components applicable across diverse scenarios. They are cost-effective, readily available, and come in a broad spectrum of wattage ratings, tolerances, and temperature coefficients. Jotrin is an electronic parts supplier that sells resistors from various manufacturers, including Murata and Vishay. Jotrin provides information on stock availability, pricing, and datasheets for resistors. To learn more, please visit the Jotrin Resistors page.

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