Common Base Current Gain Alpha — the NEET Physics formula with its derivation, variables, validity constraints and worked solver.
Common Base Current Gain (Alpha) Applicable to Bipolar Junction Transistors (BJT) operating in the active region specifically in the common base configuration. Identify the common base configuration where emitter is the input terminal and collector is the output terminal. Apply the definition of DC current gain as the ratio of output current to input current. Use the relation I E = I B + I C to show alpha = (I E - I B) / I E. I E = I C + I B Alpha is always less than 1 Temperature dependent Thinking alpha can be greater than unity. Confusing alpha with beta (common emitter gain).