Question

In the case of constants $\alpha$ and $\beta$ of a transistor

• A. $\alpha$ = $\beta$
• B. $\beta$ < 1 ; $\alpha$ > 1
• C. $\alpha$\beta$ = 1
• D. $\beta$ > 1 ; $\alpha$ < 1

Answer 1

The correct option is D $\beta$ > 1 ; $\alpha$ < 1

Alpha $\left(\alpha \right)$ : it is the ratio of collector current variations to emitter current variations. when no load and voltage be constant.
e.g., $\alpha =\frac{I_c}{I_e}$
Where , $I_c$ is collector current variations, $I_e$ is the emitter current variations

Beta $\left(\beta \right)$ : it is the ratio of collector current variations to base current variations on no load and constant voltage.
e.g., $\beta =\frac{I_c}{I_b}$
Now, the relationship between alpha and beta
$$\beta =\frac{\alpha }{1-\alpha }$$
or,$$\alpha =\frac{\beta }{\beta +1}$$
from above relation it is clear that ,
α < 1 and β > 1