Question

Define current ratio $\alpha$ and $\beta$ for transistor. obtain the relation between them.

Answer 1

The current gaain in the CE circuit is called $\left(\beta \right)$

$\beta$ is the relationship of collector current (out put current is base current (input current)

To calculate $\beta$

$\beta =\frac{△Ie}{△I}$

The current gain in the LB circuit is calculate in a method similar to that of the common emiiffer except that the input current to $I_E$ not n and $\alpha$ used in place of $\beta$ for gain

$\alpha$ is the relationship of collector current (output) to emitter current (input)

$\alpha =\frac{△I_e}{△Y{I}_E}$

thus

$\alpha =\frac{\beta }{\beta +1}$