In a bipolar transistor, alpha is the ratio of:

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RRB ALP Electronics Mechanic 21 Jan 2019 Official Paper (Shift 3)
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  1. collector current to emitter current
  2. emitter current to collector current
  3. base current to collector current
  4. collector current to base current

Answer (Detailed Solution Below)

Option 1 : collector current to emitter current
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Bipolar Junction Transistor (BJT)

 

F4 Vinanti Engineering 06.02.23 D13

BJT is a current-controlled device.

BJT is a three-terminal device i.e. base, collector, and emitter.

The conduction in BJT is due to the minority as well as the majority charge carrier.

Current ratios in BJT

1.) Common base current gain

It is the ratio of collector current to emitter current.

It is denoted by α

\(α={I_C\over I_E}\)

2.) Common emitter current gain

It is the ratio of collector current to base current.

It is denoted by β

\(β={I_C\over I_B}\)

3.) Common collector current gain

It is the ratio of emitter current to base current.

It is denoted by γ 

\(γ={I_E\over I_B}\)

Also, γ = α + β 

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