Define α and β of the transistor.

Define α and β of the transistor. 
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Answer :

α: The ratio of collector current IC to emitter current IE for a constant collector to base voltage VCB in the CB configuration is called current gain alpha (α). 

 β : The ratio of collector current IC to base current IB for a constant collector to emitter voltage VCE in the CE configuration is called current gain beta (β) .
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