Transistors

Step 1: Apply Kirchhoff’s Voltage Law (KVL) to the input loop.
In the given circuit, the emitter current can be found by first analyzing the base current . According to the problem, the voltage drop across the emitter resistor is given as 0.3 V. From this, the emitter current is:
Step 2: Use the current gain to find the collector current.
The current gain of the transistor is given as 100, and the base current is related to the collector current by the relation: To calculate , we can use the voltage drop across the base resistor , which is . The voltage across is: where . Solving for , we find:
Step 3: Conclusion.
The emitter current is the sum of the base current and the collector current, and using the relation for , the total emitter current is approximately 2.5 μA.

Step 1: Understanding transistor resistances.
In a transistor used as an amplifier, the base-emitter junction should have a low resistance for efficient current flow, and the base-collector junction should have a high resistance to ensure high gain.
Step 2: Identifying the correct resistances.
For optimal amplifier performance, is low, and is high. This corresponds to option (B).