Question

For a transistor, the current ratio ${\alpha }_{DC}$ is $\frac{69}{70}$. The current gain ${\beta }_{DC}$ is

• A. 66
• B. 67
• C. 69
• D. 71

Answer 1

The correct option is C 69

Given : ${\alpha }_{DC}=\frac{69}{70}$

The current gain, ${\beta }_{DC}=\frac{{\alpha }_{DC}}{1-{\alpha }_{DC}}$

${\beta }_{DC}=\frac{\frac{69}{70}}{1-\frac{69}{70}}=69$