53.2.3. Effect on Input Resistance and Voltage Gain

Try these first

1. 1.

   What is the role of the coupling capacitor in an amplifier circuit?

   Hint

   Think about how AC and DC interact in circuits.

2. 2.

   How does removing the coupling capacitor affect input resistance?

   Hint

   Consider what happens when AC ground is removed.

3. 3.

   What happens to the input resistance when the coupling capacitor is removed?

   • It decreases
   • It stays the same
   • It increases

   Hint

   Think about the effects of AC grounding.

4. 4.

   True or False: The voltage gain increases when you remove the coupling capacitor.

   • True
   • False

   Hint

   Consider what effects the capacitor has on signal coupling.

5. 5.

   If a common base amplifier has a voltage gain of 100 with a coupling capacitor but drops to 10 without it, calculate the percentage decrease in voltage gain.

   Hint

   Use the formula for percentage change to simplify your calculation.

6. 6.

   Assuming an input resistance of 50 ohms with a capacitor and 500 ohms without it, explain the implications of this difference in an amplifier's performance.

   Hint

   Think about how input resistance affects signal integrity.