29.4. CE Amplifier with Cell Biased Circuit

Try these first

1. 1.

   Define input resistance in a common emitter amplifier.

   Hint

   Refer to the parallel combination of resistances.

2. 2.

   Calculate the voltage gain if g_m is 150 mA/V and R_C is 2 kΩ.

   Hint

   Use the formula A_v = -g_m × R_C.

3. 3.

   What is the significance of a negative voltage gain in a CE amplifier?

   • It amplifies the signal positively.
   • The output is inverted.
   • It has no significance.

   Hint

   Think about the nature of CE amplifiers.

4. 4.

   Input resistance is critical because it affects signal coupling into the amplifier.

   • True
   • False

   Hint

   Consider how resistances work in parallel.

5. 5.

   Given that R_C is 5 kΩ and g_m is 200 mA/V, calculate the voltage gain and explain how it would change if R_C is halved.

   Hint

   Use the voltage gain formula to find changes with the modified resistors.

6. 6.

   A common emitter amplifier experiences power dissipation at 12 V with a collector current of 3 mA. Calculate the power loss and discuss the implications for circuit design.

   Hint

   Review how voltage and current interact to produce power.