For a CE-transistor amplifier, the audio signal voltage across the collected resistance of 2k is 2 V. Suppose the current the amplification factor of the transistor is 100, find the input signal voltage and base current, if the base resistance is 1k.
Given that,
Rc = 2K-Ω = 2000 Ω (Collector Resistance)
V = 2 Volts (Audio signal voltage across the collector resistance)
β = 100 (Current amplification factor of the transistor)
RB = 1K-Ω (Base resistance)
Let, the Input signal voltage be Vi
Base current = IB
We have the relation for voltage amplification as:
⇒ 
⇒ 
⇒Vi = 0.01 V
Therefore, the input signal voltage of the amplifier is 0.01 V.
We know that Base Resistance:
RB = Vi/IB
⇒ IB = Vi/RB = 0.01 V/1000Ω = 10μA
Therefore, the base current of the amplifier is 10μA