<P> The standard voltage divider circuit discussed above faces a drawback--AC feedback caused by resistor R reduces the gain . This can be avoided by placing a capacitor (C) in parallel with R, as shown in circuit diagram . The result is that the DC operating point is well controlled, while the AC - gain is much higher (approaching β), rather than the much lower (but predictable) value of R c / R e (\ displaystyle R_ (\ text (c)) / R_ (\ text (e))) without the capacitor . </P> <P> When a split supply (dual power supply) is available, this biasing circuit is the most effective, and provides zero bias voltage at the emitter or collector for load . The negative supply V is used to forward - bias the emitter junction through R . The positive supply V is used to reverse - bias the collector junction . Only two resistors are necessary for the common collector stage and four resistors for the common emitter or common base stage . </P> <P> We know that, </P> <P> V − V = V </P>

The higher the stability factor the network to variation in that parameter is