In a transistor, the change produced in collector current is 3 mA, when the base current is changed by 60 μA. This transistor is used as a common emitter amplifier with a load resistance of 5 KΩ. The input resistance of this silicon transistor is 50 Ω. The voltage gain of the amplifier is: |
2000 500 200 5000 |
5000 |
The correct answer is Option (4) → 5000 To calculate the voltage gain of an amplifier, $A_v=\frac{ΔV_{out}}{ΔV_{in}}=\frac{ΔI_C.R_L}{ΔI_B.r_{in}}$ $∴A_v=\frac{(3×10^{-3}A)(5000Ω)}{(60×10^{-6}A).50Ω}$ $=\frac{15V}{3mV}=5000$ |