Discussion Forum

 The input resistance of a common emitter amplifier is 330 Ω and the load resistance is 5 k Ω. A change of base current is 15 μ A results in the change of collector current by 1 mA. The  voltage gain of the amplifier is 

Answer:

Explanation:

 Given,  $\triangle I_{C}= 1mA=10^{-3}$  A

 $\triangle I_{b}= 15\mu A=15\times 10^{-6} A$

 $R_{L}= 5k$ Ω =5 x 10³ Ω

 Ri= 330 Ω

 the voltage gain of an amplifier

 $A_{r}=\frac{\triangle I_{c}\times R_{L}}{\triangle I_{b}\times R_{i} }$

 = $\frac{10^{-3}\times5\times 10^{3}}{15 \times 10^{-6}\times330}=1010$