The output characteristics of a transistor
Question:

The output characteristics of a transistor is shown in the figure. When $\mathrm{V}_{\mathrm{CE}}$ is $10 \mathrm{~V}$ and $1_{\mathrm{C}}=4.0 \mathrm{~mA}$, then value of $\beta_{\mathrm{ac}}$ is

Solution:

$\Delta \mathrm{I}_{\mathrm{B}}=(30-20)=10 \mu \mathrm{A}$

$\Delta \mathrm{I}_{\mathrm{C}}=(4.5-3) \mathrm{mA}=1.5 \mathrm{~mA}$

$\beta_{\mathrm{ac}}=\frac{\Delta \mathrm{I}_{\mathrm{C}}}{\Delta \mathrm{I}_{\mathrm{B}}}=\frac{1.5 \mathrm{~mA}}{10 \mu \mathrm{A}}=150$

$\beta_{\mathrm{ac}}=150$