Question

Graph of input characteristic of common emitter amplifier is

• A.
• B.
• C.
• D.

Answer 1

Answer: (B)

Answer 2

The input characteristics of common emitter amplifier is-the curve between base current $I_{B}$ and base-emitter voltage $V_{B E}$ at constant collector-emitter voltage $V_{C E} .$ The input characteristics can be determined: by the circuit shown in figure. Keeping $V_{C E}$ constant (say at $0 V$ ), note the base current $I_{B}$ for various values of $V_{B E}$. Then, plot the readings obtained on the graph, taking $I_{B}$ along Y-axis and $V_{B E}$ along X-axis. This gives the input characteristic at $V_{C E}=0 V$. Following a similar procedure, a family of input characteristics can be drawn. These curves are similar to as shown in option.