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JEE Main201912 Apr 2019Evening ShiftPhysicsCommunication SystemActual

In a CE transistor amplifier, the audio signal voltage across the collector resistance of 2 kΩ is 2 V , if the base resistance is 1 kΩ and the current amplification of the transistor is 100 then the input signal voltage is

Options

  1. A10   mV
  2. B1   mV
  3. C0 .1   V
  4. D1  V

Correct answer

A. 10   mV

Step-by-step solution

Current amplification factor, β = Δ I C Δ I B Collector current, Δ I C = 2 V 2 × 10 3 Ω = 1 × 10 - 3   A Base current, Δ I B = V B R B = V B 1 × 10 3 = V B × 10 - 3 Given, β = 100 Now, 100 = 10 - 3 V B × 10 - 3 ⇒ V B = 1 100   V = 10   mV

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