Experiment -8 :- Resistor Color Code And verifying that value with a multimeter.

 To calculate a resistor's value, you can perform a simple experiment using its color bands. The color code on a resistor acts like a key, with each color representing a number, multiplier, or tolerance.

Resistor Color Code Chart

The standard resistor color code is based on a mnemonic to help you remember the values for each color: "BBROY G. Great Britain. Violet. Gray. White." The first letter of each word corresponds to a color: Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Gray, White.

Color	Digit	Multiplier	Tolerance (%)
Black	0	100 (1)	-
Brown	1	101 (10)	±1%
Red	2	102 (100)	±2%
Orange	3	103 (1k)	-
Yellow	4	104 (10k)	-
Green	5	105 (100k)	±0.5%
Blue	6	106 (1M)	±0.25%
Violet	7	107 (10M)	±0.1%
Grey	8	108 (100M)	±0.05%
White	9	109 (1G)	-
Gold	-	10−1 (0.1)	±5%
Silver	-	10−2 (0.01)	±10%
None	-	-	±20%

---

Experiment Procedure

This experiment involves two main parts: calculating the resistance from the color code and verifying that value with a multimeter.

Materials

• Several resistors with different color bands

• A digital multimeter (DMM) with an ohmmeter function

• A resistor color code chart (like the one above)

Steps

1. Select a Resistor: Choose a resistor. Hold it so the gold or silver tolerance band is on the right side. If there's no tolerance band, the band closest to the end is the first one.

   
   
   

2. Read the Color Bands:

   • Band 1 (First Digit): Note the color of the first band and find its corresponding digit from the chart. This is the first significant figure.

   • Band 2 (Second Digit): Note the color of the second band and find its corresponding digit. This is the second significant figure.

   • Band 3 (Multiplier): Note the color of the third band and find its multiplier value from the chart.

   • Band 4 (Tolerance): Note the color of the fourth band and find its tolerance value from the chart. This indicates the percentage of variation from the calculated resistance.

3. Calculate the Nominal Resistance: Combine the values. The first two digits form a number, which you then multiply by the third band's multiplier.

   • Formula: Resistance = (1st digit)(2nd digit) x Multiplier

   • Example: A resistor with bands Red, Red, Orange, Gold.

     • Red = 2

     • Red = 2

     • Orange = 103

     • Gold = ±5%

     • Calculation: $(2)(2)\times 10^3=22\times 1000=22,000\Omega$ or 22 k$\Omega$.

     • The tolerance is ±5%, so the actual resistance should be between $22,000\times 0.95=20,900\Omega$ and $22,000\times 1.05=23,100\Omega$.

4. Measure with a Multimeter:

   • Set the multimeter to the ohmmeter setting (Ω).

   • Connect the probes to the resistor's two leads. The orientation doesn't matter for a resistor.

   • Read the value displayed on the multimeter screen. This is the measured value.

5. Analyze the Results: Compare the measured value from the multimeter to the nominal value you calculated from the color code. The measured value should fall within the tolerance range.

• To calculate the deviation (percentage error):