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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Detailed Solution

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Bipolar Junction Transistor (BJT)

 

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

2.) Common emitter current gain

It is the ratio of collector current to base current.

It is denoted by β

3.) Common collector current gain

It is the ratio of emitter current to base current.

It is denoted by γ 

Also, γ = α + β 

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