Identifying Resistors

Identifying, testing and combining resistors

Resistors are a piece of apparatus used mainly to add resistance to a circuit. Resistors are identified by a code using the colour and position of the bands on the resistor itself. To calculate the total resistance a resistor can hold, you use the colour coded bands to figure it out. The first two or three bands are the numbers to write down. The next band is the multiplier (how many zeros to add to the number) a gold multiplier makes one decimal place smaller, silver makes two decimal places smaller. The last band is the tolerance values. So if I had a resistor with the colour coding of green, blue, brown and gold, by using my table I can figure out this resistors low and high tolerance values.

·         GREEN=5

·         BLUE= 6

·         BROWN= 1 ZERO

The gold band is the indicator of which end to read from. So my value to start off with for figuring out this resistor is 560, now to calculate the low tolerance value you must minus 5% of that 560 from 560, so 5% of 560 is 28, so I minus 28 from 560, which gives me the low tolerance value of 532. To find out the high tolerance level, I add that 28 (5%) back onto the original 560 which gives me a high tolerance value of 588. To test that the resistor is working connect it to a multimeter set on Ohms range and if the value falls between that 532 and 588, you have a working resistor.