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The current gain β for a common emitter amplifier is 69 . If the emitter current is 7 mA , the base current is

Options

  1. A0.1 mA
  2. B1 mA
  3. C0.2 mA
  4. D2 mA

Correct answer

A. 0.1 mA

Step-by-step solution

Here, β = 69 I E = 7 mA Since, β = α 1 - α 69 = α 1 - α 69 - 69 α = α 69 = 70 α α = 69 70 = 0 .986 I C I E = 0 .986 ∴ I C = 0 .986 I E = 0 .986 × 7 = 6 .9 mA ∴ I B = I E - I C = 7 - 6 .9 = 0 .1 mA

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