Question

In common emitter amplifier, using output resistance \(5000\) \(\Omega\) and input resistance \(2000\) \(\Omega\), if the peak value of input signal voltage is \(10\) mV and \(\beta =50\), then peak value of output voltage is

• A. \(5\times 10^{-6}\) V
• B. \(12.50\times 10^{-6}\) V
• C. \(1.25\) V
• D. \(125.0\) V

Hint:

Voltage gain equals current gain times the ratio of output to input resistance.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
In a common emitter amplifier the voltage gain is \(A_v = \beta \dfrac{R_{out}}{R_{in}}\).

Step 2: Voltage Gain
\(A_v = 50 \times \dfrac{5000}{2000} = 125\)

Step 3: Output Voltage
\(V_{out} = A_v \times V_{in} = 125 \times 10\times 10^{-3} = 1.25\) V

Step 4: Compare the options
The peak output voltage is \(1.25\) V, option (C).

Final Answer:
The peak output voltage is 1.25 V. \[ \boxed{\text{(C) }1.25\ \text{V}} \]