14.9: For a CE-transistor amplifier, the audio signal voltage across the collected resistance of 2 kΩ is 2 V. Suppose the current amplification factor of the transistor is 100, find the input signal voltage and base current, the base resistances 1 kΩ.

Hint: \(I_{B}=\frac{I_{C}}{\beta }\)
Step 1: Find the input voltage.
\(\frac{V_{0}}{V_{i} }=\frac{R_{0}}{R_{i} }\times\beta\)
\(\Rightarrow~V_{i} =10~ mV\)
Step 2: Find collector current.
\(I_{C}=\frac{V_{0}}{R_{0}}=\frac{2}{2}=1~mA\)
Step 3: Find base current.
\(I_{B}=\frac{I_{C}}{\beta }=\frac{1\times10^{-3}}{100}=~10~\mu A\)