Question

A transistor connected in common emitter mode,the voltage drop across the collector is 2V and $\beta$ is 50, the base current if $R_{C}$ is $2k\Omega$ is

• A. $40\mu A$
• B. $20\mu A$
• C. $30\mu A$
• D. $15\mu A$

Answer 1

Answer: (B)

$20\mu A$

Answer 2

: using , $I_{C} = \frac{V_{CE}}{R_{C}} = \frac{2}{2 \times 10^{3}} = 10^{- 3} = 1mA$

$\therefore\beta = \frac{I_{C}}{I_{B}}$

$I_{B} = \frac{I_{C}}{\beta} = \frac{10^{- 3}}{50}A = 20\mu A$