Question

The current gain for a common emitter amplifier is $69.$ If the emitter current is $7mA,$ the base current is:

• A. $0.1mA$
• B. $1mA$
• C. $0.2mA$
• D. $2mA$

Answer 1

Answer: (A)

$\gamma =\frac{I_E}{I_B}=1+\beta =1+69=70$
Base current, $I_B=\frac{I_E}{\gamma }=\frac{7}{70}mA=0.1mA$