Identifying, Testing and Combining Resistors

Identify the colour code on the resistors:

Ref: Http://www.auschristmaslighting.com.au/index.php?title=File:Resistor_colour_codes.gif

  black=0, brown=1, red=2, orange=3, yellow=4, green=5, blue=6, violet=7, grey=8, white=9
  gold=5%, silver=10%, brown=1%, red=2%, green=0.5%, blue=0.25%, 0.1%=0.1% for tolerance
  brown=100ppm, red=50ppm, orange=15ppm, yellow=25ppm for temperature coefficient.

   To identify the resistance of the resistor, first write down first two or three numbers, then add many zero

   as the third or the forth colour code showed. The last colour shows the tolerance normally

  e.g  the resistor with colour code which are brown, black, orange and gold.
       1: the gold is 5% tolerance.
       2: the orange means 3 zeros
       3: brown is 1 and black is 0
       4: Add 3 zeros after 1(brown) 0(black), so the resistance is 10000 ohm with 5% tolerance.

   There is a problem,  some times we can not read the colour code in right queue, so we should measure the      
    resistance by multimeter.

The colour code of this resistor from left to right are:
yellow, violet, black, black, brown. the reading should be 470ohm 1% tolerance.










The colour code for the same resistor from left to right are: brown, black, black, violet, yellow.
now the reading should be: 10ohm 0.1% tolerance and 25ppm.






                                       So, i measured the resistance and reading is 468.9ohm.

Identify 6 resistor:
1. Brown Black Orange Gold
    10000R and 5% tolerance  measuring: 10000R
2. Red Red Red Gold
    2200R and 5% tolerance measuring: 2180R
3. Yellow Violet Black Black Brown
    470R and 1% tolerance measuring: 46809R
4. Brown Black Red Gold
   1000R abd 5% tolerance measuring: 1006R
5. Green Blue Green Gold
   5600000R and 5% tolerance measuring: 5.658MR
6. Brown Black Brown Gold
   100R and 5% tolerance measuring: 99.8R


Combining the resistor:

      In series circuit

I chose one 1000ohm resistor and one 470ohm resistor, put them in series.
The total resistance in series circuit is the sum of all resistance in the circuit.
The calculated total resistance is 1000ohm + 470ohm = 1470ohm.
Then i measured the total resistance the reading is: 1462ohm.

     In parallel circuit

I put same resistors in parallel circuit this time.
The total resistance in parallel circuit is lower than any resistor in the circuit, and can be calculated by formula: 1/Rt = 1/R1 + 1/R2 +.......1/Rn
The calculated total resistance is:
      1/Rt = 1/1000ohm + 1/470ohm
      Rt=319.73ohm
The measured total resistance is 318.8ohm.