only one dc supply is necessary. Operating point is almost independent of β variation. Operating point stabilized against shift in temperature.
Two words divider and bias. A divider is usually used to get a bias voltage.
Its the most stable biasing which is free from transistor parameters. Calculations are also simple. That's why its widely used.
This arrangement is called SELF-BIAS. Now, if an increase of temperature causes an increase in collector current, the collector voltage (VC) will fall because of the increase of voltage produced...
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