2016 Phase II Semiconductor ElectronicsCE amplifier – voltage gain Easy Question 10 of 12 in Semiconductor Electronics

For CE transistor amplifier, the audio signal voltage across the collector resistance of 2 k$\Omega$ is 4 V. If the current amplification factor of the transistor is 100 and the base resistance is 1 k$\Omega$, then the input signal voltage is:

A 30 mV
B 15 mV
C 10 mV
D 20 mV

The answer is D.

Solution

$A_V = \beta R_C/R_B = 200$.

$\beta = 100$; $V_0 = 4$ V; $R_i = 10^{3}\ \Omega$; $R_0 = 2\times10^{3}\ \Omega$
$\frac{V_0}{V_i} = \beta\frac{R_0}{R_i} \Rightarrow \frac{4}{V_i} = 100\times\frac{2\times10^3}{10^3}$
$V_i = 20$ mV

Concept ce-amplifier-input-voltage

Semiconductor Electronics in past papers

12 questions from this chapter have appeared across 3 exam years.