In the study of transistor as amplifier, if $α=\frac{I_C}{I_E}$ and $β=\frac{I_C}{I_B}$, where $I_C,I_B$ and $I_E$ are the collector, base and emitter currents, then
Answer & explanation
Correct answer: option 3
As we know that $I_e = I_c + I_b$
Divide both side by $I_e$
$\frac{I_e}{I_c}=1+\frac{I_b}{I_c}⇒\frac{1}{α}=1+\frac{1}{β}$
$β=\frac{α}{1-α}$