53.1.1. Common Base and Common Gate Amplifiers (Contd.): Numerical Examples (Part C)

Try these first

1. 1.

   What is the role of coupling capacitors in amplifiers?

   Hint

   Think about grounding in circuits.

2. 2.

   How does the presence of a capacitor affect input resistance?

   Hint

   Consider the flow of signal through the capacitor.

3. 3.

   What is the expected consequence of removing the coupling capacitor for input resistance?

   • Input resistance decreases
   • Input resistance stays the same
   • Input resistance increases

   Hint

   Consider what happens to voltage flow.

4. 4.

   True or False: Removing a coupling capacitor always decreases output impedance.

   • True
   • False

   Hint

   Think about the output paths and resistances.

5. 5.

   Given an amplifier circuit operates with a voltage gain of 108 with a coupling capacitor, predict the new gain if the capacitor is removed, and explain why.

   Hint

   Use the factors discussed in class regarding voltage gain reduction.

6. 6.

   If an amplifier's input and output impedances are critically tied to its configuration, assess how one would calculate the new output impedance without the presence of capacitors.

   Hint

   Explore resistances that tend to dominate the path through which signal flows.