Question 239: Semiconductors and Logic Gates

Question

For a common emitter configuration, if $$\alpha $$ and $$\beta $$ have their usual meanings, the incorrect relationship between $$\alpha $$ and $$\beta $$ is :

Accepted Answer

We know, collector current is given as $${I_C} = \beta {I_B}$$
Also, $${I_C} = \alpha {I_E}$$
Ã¢ÂÂUsing, $${I_E} = {I_B} + {I_C}$$
$${{{I_C}} \over \alpha } = {{{I_C}} \over \beta } + {I_C}$$
Solving above equations,
$${1 \over \alpha } = {1 \over \beta } + 1$$
$$\alpha  = {\beta  \over {1 + \beta }}$$

Answer

$$\alpha  = {\beta  \over {1 + \beta }}$$

Answer

$$\alpha  = {{{\beta ^2}} \over {1 + {\beta ^2}}}$$

Answer

$${1 \over \alpha } = {1 \over \beta } + 1$$

Answer

$$\alpha  = {\beta  \over {1 - {\beta ^2}}}$$

Semiconductors and Logic Gates

For a common emitter configuration, if $\alpha and \beta have their usual meanings, the incorrect relationship between \alpha and \beta $ is :

Choose the correct answer: