An n – p – n transistor circuit has $α$ = 0.985.
If $I_c = 2mA$, then value of $I_b$ is -
Answer & explanation
Correct answer: option 1
$α=\frac{I_c}{I_e}=\frac{I_c}{I_c+I_b}=0.985$
$I_c = 0.985 (I_c + I_b)$
$I_c = 0.985\, I_c + 0.985\, I_b$
$0.985 I_b = 0.015 I_c = 0.015 × 2 mA$
$I_b = \frac{0.015 ×2}{0.985}= 0.03 mA$
$I_b≈0.03mA$