Question

The dc common emitter current gain of a n-p-n transistor is 50. The potential difference applied across the collector and emitter of a transistor used in CE configuration is, $V_{CE} = 2 \, V$. If the collector resistance,$RC = 4 \, k \Omega$, the base current $(I_B)$ and the collector current $(I_C )$ are

• A. $I_B = 10 \, \mu A, I_C = 0.5 \, mA$
• B. $I_B = 0.5 \, \mu A, I_C = 10 \, mA$
• C. $I_B = 5 \, \mu A, I_C = 1 \, mA$
• D. $I_B = 1 \, \mu A, I_C = 0.5 \, mA$

Answer 1

Answer: (A)

$I_c = \frac{ V_{CE}}{R_{C}} = \frac{2}{4 \times 10^3} $
$= 0.5 \times 10^{-3} \,A = 0.5 \,mA$
$\beta =\frac{I_C}{I_B}$
$ \Rightarrow I_{B} = \frac{I{c}}{\beta} = \frac{0.5\times 10^{-3}}{50}$
$ = 10^{-5} \,A = 10\, \mu A $