9.4.1. Review of NPN and PNP Transistors

Try these first

1. 1.

   Describe the structure of an NPN transistor.

   Hint

   Think about the arrangement and flow direction of charge carriers.

2. 2.

   What does forward bias mean?

   Hint

   Consider the conditions necessary for current flow.

3. 3.

   What configuration does an NPN transistor have?

   • P-N-P
   • N-P-N
   • N-P-P

   Hint

   Think about the order of layers.

4. 4.

   In a PNP transistor, the emitter must be at a higher voltage relative to which other terminal?

   • Collector
   • Base
   • Both

   Hint

   Recall the biasing definitions.

5. 5.

   A circuit uses an NPN transistor with a beta (β) of 50 and a base current (Ib) of 5 µA. Calculate the collector current (Ic) and the relations among emitter, base, and collector currents.

   Hint

   Remember, Ic = β * Ib and relate the currents together.

6. 6.

   In a PNP transistor, if the emitter current (Ie) is measured at 3 mA and the base current (Ib) is 10 µA, determine the collector current (Ic) assuming β = 300.

   Hint

   Understand the relationship between currents in the transistor.