45.2.2. Input Capacitance and Voltage Gain

Try these first

1. 1.

   What is input capacitance?

   Hint

   Think about what happens when a signal comes into the amplifier.

2. 2.

   Define voltage gain.

   Hint

   It tells us how much the amplifier amplifies the signal.

3. 3.

   What is the main characteristic of a common collector amplifier?

   • It amplifies current
   • It enhances voltage gain
   • It has low input resistance

   Hint

   Think about the function of collectors in amplifiers.

4. 4.

   True or False: In a common drain amplifier, the output voltage is significantly higher than the input voltage.

   • True
   • False

   Hint

   Consider what the term 'common drain' implies for voltage levels.

5. 5.

   A common collector amplifier has an input capacitance of 4pF and a voltage gain of approximating 0.95. Calculate the effective input capacitance when considering additional capacitance of 1pF.

   Hint

   Don't forget to calculate the contribution of added capacitance based on the gain.

6. 6.

   Design a mathematical model that reflects the variations in output resistance for a common collector amplifier with a variable load resistance affecting output significantly. Show your workings.

   Hint

   Focus on parallel resistance calculations for simplifications.