In a common-emitter transistor amplifier, the audio signal voltage across the collector is $3 ext{ V}$. The r

Question

In a common-emitter transistor amplifier, the audio signal voltage across the collector is $3	ext{ V}$. The resistance of the collector is $3	ext{ k}\Omega$. If the current gain is $100$ and the base resistance is $2	ext{ k}\Omega$, the voltage and power gain of the amplifier are:

Accepted Answer

1. **Identify the Given Data:** 
   * Collector resistance (output resistance), $R_c = 3	ext{ k}\Omega$
   * Base resistance (input resistance), $R_b = 2	ext{ k}\Omega$
   * Current gain, $\beta = 100$
   * *(Note: The $3	ext{ V}$ collector voltage is extra information not needed for finding the gains if $\beta$ and the resistances are known).* 
2. **Calculate Voltage Gain ($A_v$):** The voltage gain in a common-emitter amplifier is the product of current gain and resistance gain.
   * $A_v = \beta 	imes \frac{R_c}{R_b}$
   * $A_v = 100 	imes \frac{3	ext{ k}\Omega}{2	ext{ k}\Omega} = 100 	imes 1.5 = 150$
3. **Calculate Power Gain ($A_p$):** The power gain is the product of current gain and voltage gain.
   * $A_p = \beta 	imes A_v$
   * $A_p = 100 	imes 150 = 15000$
4. **Conclusion:** The voltage gain is $150$ and the power gain is $15000$.

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