In a transistor circuit, a milliammeter in the collector lead reads 3.60 mA and a microammeter in…

In a transistor, $I_E = I_B + I_C$, $\alpha = \dfrac{I_C}{I_E}$ and $\beta = \dfrac{I_C}{I_B}$, with $\beta = \dfrac{\alpha}{1 - \alpha}$. In the common-emitter circuit, $V_{BB} = I_B R_B + V_{BE}$ and $V_{CC} = I_C R_C + V_{CE}$, with $V_{BE} = 0.7$ V for silicon. The input resistance is $r_i = \left(\dfrac{\Delta V_{BE}}{\Delta I_B}\right)_{V_{CE}}$ and the output resistance is $r_o = \left(\dfrac{\Delta V_{CE}}{\Delta I_C}\right)_{I_B}$.