Question

In a common emitter amplifier, using output resistance of $5000\Omega$ and input resistance of $2000\Omega$ , if the peak value of input signal voltage is $10 \, mV$ and $\beta =50$ is given. Find peak value of output voltage -

• A. $5\times 10^{- 6}V$
• B. $2.5\times 10^{- 4} \, V$
• C. $1.25 \, V$
• D. $125 \, V$

Answer 1

Answer: (C)

for CE amplifier
Voltage gain $A=\beta \left(\frac{R_{o}}{R_{i}}\right)$
$A=50\times \left(\frac{5000}{2000}\right)$ ;
$A=125=\frac{v_{o u t p u t}}{V_{i n p u t}}$ ;
$125=\frac{V_{0}}{10 m V}$ ;
$V_{0}=1.25V$