Question

The current gain of a common emitter amplifier is $69$ . If the emitter current is $7.0 \,mA$, collector current is :

• A. 9.6 mA
• B. 6.9 mA
• C. 0.69 mA
• D. 69 mA

Answer 1

Answer: (B)

6.9 mA

Answer 2

$\beta=69=\frac{I_{C}}{I_{B}}$ $\alpha=\frac{\beta}{1+\beta}=\frac{69}{70}=\frac{I_{C}}{I_{E}}$ $I_{C}=I_{E}\times\frac{69}{70}$ $=\frac{69}{70}\times7$ $=6.9$ mA