9.4. Summary of Concepts

Try these first

1. 1.

   Define what an n-p-n transistor is.

   Hint

   Remember the layers' arrangement.

2. 2.

   What is the purpose of biasing in transistors?

   Hint

   Think about the importance of operational states.

3. 3.

   Which of the following describes the function of the base in a transistor?

   • To amplify the output current
   • To isolate the collector and emitter
   • To control the flow of current
   • None of the above

   Hint

   Think about the role of the small current in regulating larger currents.

4. 4.

   True or False: In a p-n-p transistor, the collector current enters through the emitter.

   • True
   • False

   Hint

   Recall the current flow directions in n-p-n and p-n-p transistors.

5. 5.

   Analyze a circuit containing a p-n-p transistor with an emitter voltage of +10V, a base voltage of +7V, and a collector voltage of +5V. What are the biases, and is the transistor in the active region?

   Hint

   Check if voltage conditions meet active region requirements.

6. 6.

   Design an n-p-n transistor circuit using a supply voltage of 12V. If you have a resistor of 2kΩ in the base, determine the emitter current assuming beta = 100.

   Hint

   Begin with Ohm's Law to find base current first.