JEE PYQ: Semiconductors Question 4
Question 4 - 2021 (18 Mar 2021 Shift 2)
The correct relation between $\alpha$ (ratio of collector current to emitter current) and $\beta$ (ratio of collector current to base current) of a transistor is:
(1) $\beta = \frac{\alpha}{1+\alpha}$
(2) $\alpha = \frac{\beta}{1-\alpha}$
(3) $\beta = \frac{1}{1-\alpha}$
(4) $\alpha = \frac{\beta}{1+\beta}$
Show Answer
Answer: (4)
Solution
$\alpha = I_C/I_E$, $\beta = I_C/I_B$, $I_E = I_B + I_C$. So $\alpha = I_C/(I_B + I_C) = 1/(I_B/I_C + 1) = \beta/(1+\beta)$.
BETA
