Question

For a transistor connected in common emitter mode [CE] the slope of the input characteristic curve gives :

• A. Input impedance
• B. Current gain
• C. Reciprocal of input impedance
• D. Voltage gain

Answer 1

Answer: (C)

Reciprocal of input impedance

The input characteristic curve of a transistor in CE configuration is a plot of emitter current, $I_E$ with respect to the base-emitter voltage, $V_{BE}$.

Hence the slope of the curve $=\frac{I_E}{V_{BE}}$ $=\frac{1}{V_{BE}/I_E}$ $=\frac{1}{Z}$ where $Z$ is input impedance $=\frac{V_{BE}}{I_E}$

Hence correct answer is option C.