For CE transistor amplifier, the audio signal voltage across the collector resistance of 4 l is 5 ~V . If the current amplification factor of the transistor is 100 and base resistance is 2 k , then input signal voltage is

Step-by-step solution

Given the collector resistance R_C = 4 k = 4000 , the output voltage V_o = 5 V , and the current amplification factor = 100 . The collector current I_C is given by I_C = V_o R_C = 5 4000 A = 1.25 10⁻³ A = 1.25 mA . The base current I_B is related to the collector current by I_C = I_B . Thus, I_B = I_C = 1.25 mA 100 = 0.0125 mA = 1.25 10⁻⁵ A . The input signal voltage V_i is given by V_i = I_B R_B , where R_B = 2 k = 2000 . V_i = (1.25 10⁻⁵ A ) (2000 ) = 2.5 10⁻² V = 25 mV . Answer: 25 mV