Question

A transistor has current gain of 0.99 when used in common base (cb) configuration. how much will be the current gain of this transistor in common emitter (ce) configuration ?

Answer 1

Current gain in CB= $\beta$
Current gain in CE= $\alpha$

Relation between $\beta$ and $\alpha$-

$\alpha = \dfrac{\beta}{1 + \beta}$
or, $\alpha = \dfrac{0.99}{1 + 0.99}$

or, $\alpha = \dfrac{0.99}{1.99}$
or, $\alpha = 0.497$

So, the current gain in CE is 0.497.