Page 30 - Testing Electronic Components
P. 30
Resistance and Resistors
The word resistance means opposition to some action. In electricity
resistance means the opposition to the flow of current. The resistance is
measured in ohm (Ω). Resistance is also expressed in kilo-ohms, milli-
ohms etc. With 1000Ω = 1 kilo ohms, 1000000Ω = 1 mega ohms. The
symbol of resistance is show as:
R
Symbol of a resistor.
It is noted by a letter R.
The main two characteristic of resistor are its resistance R in ohms and its
power rating in watts, W. Resistors are available in a very wide range of
R values from a fraction of an ohm to many mega ohms. The power
rating may be as high as several hundred watts or as low as 1/8 watt.
Always use a replacement resistor with a power rating that is equal to or
greater than the original. The value of the resistance can be measure by a
multimeter.
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