Question

In a transistor if $\frac{I_{C}}{I_{E}}=\alpha$ and $\frac{I_{C}}{I_{B}}=\beta .$ If $\alpha$ varies between $\frac{20}{21}$ and $\frac{100}{101}$, then the value of $\beta$ lies between

• A. 1-10
• B. 0.95-0.99
• C. 20-100
• D. 200-300

Answer 1

Answer: (C)

$\beta=\frac{\alpha}{1-\alpha}$
$\beta_{1}=\frac{\frac{20}{21}}{1-\frac{20}{21}}=20, $
$\beta_{2}=\frac{\frac{100}{101}}{1-\frac{100}{101}}=100$
The value of $\beta$ lies between $20-100$.