Question

In case of common emitter p-n-p transistor input characteristic is a graph drawn
A. with ${I_C}$ on y-axis and ${V_{CE}}$ on x-axis keeping ${I_B}$ constant
B. with ${I_B}$ on y-axis ${V_{BE}}$ on x-axis keeping ${V_{CE}}$constant
C. with k on y-axis ${I_B}$on x-axis keeping ${V_{CE}}$ constant
D. with on y-axis and${V_{CE}}$ x-axis keeping $I_B$ constant

Answer 1

Hint: The question is based on the common emitter p-n-p transistor where the emitter is common in both input and output circuit. The input side consists of a base and emitter. The output circuit is between emitter and collector. So; you need the input circuit parameters here to obtain the input characteristics.

Complete step by step answer:
When the emitter is common in the input circuit and the output circuit then the transistor is called the common emitter transistor. The input circuit consists of base and emitter, so the input characteristics are plotted between them. But the output also affects the input so input characteristics are drawn in consideration with output. The input characteristics are drawn by taking the reading of base currents by ammeter on emitter voltage${V_{BE}}$ with the collector to emitter voltage constant. In the common emitter p-n-p transistor, the input current is ${I_B}$; the input voltage is${V_{BE}}$ an output voltage is ${V_{CE}}$. The input characteristic is a graph plotted between the input current and the input voltage at the constant output voltage. That means the y-axis of the graph is ${I_B}$, and the x-axis of the graph is ${V_{BE}}$ on while ${V_{CE}}$ it is constant.
The input characteristics for the common emitter is such that the base current ${I_B}$ increases with increase in the emitter-base voltage${V_{BE}}$. So, in this case, the resistance is higher for the input current and voltage.

So, the correct answer is “Option B”.

Note:
Here in this question, the input characteristics are described by using the input circuit parameters.
You may go wrong in considering the input parameters between which the characteristics can be drawn.
The output also affects the input so input characteristics are drawn in consideration with output.