The collector supply voltage is 6 V and a voltage drop across a resistor of $600 \Omega$ in the collector…
The collector supply voltage is 6 V and a voltage drop across a resistor of $600 \Omega$ in the collector circuit is 0.6 V , in a circuit of transistor connected in common emitter mode. If the current gain is 20 then the base current is
0.25 mA
0.05 mA
$\quad 0.12 \mathrm{~mA}$
$\quad 0.02 \mathrm{~mA}$
Solution
For collector current, $\mathrm{I}_{\mathrm{C}}=\frac{\text { Collector voltage }}{\text { Resistance }}=\frac{0.6}{600}=1 \mathrm{~mA}$ Current gain, $\beta=\frac{I_C}{I_B}=20$
$\therefore \quad 20=\frac{1}{I_B} . \quad \Rightarrow \quad I_B=0.05 \mathrm{~mA}$