Preliminary Questions

Before performing the lab, answer the following questions. Assume you are using a 2N3904 BJT, which has $\beta \approx 200$.

1.

For the circuit in Fig. (2.3), calculate V_B, V_C and V_E if V_CC=10V, R_B=83K, R_C=500,  R_B=100 and $\beta=100$

2.

For the circuit in Fig. (2.6) calculate V_B, V_C and V_E if V_CC=15V.

3.

For the circuit in Fig. (2.7), calculate the small signal voltage gain, the input resistance and the output resistance. Let V_CC=15V.

4.

What happens to the gain of the circuit in Fig. (2.7) if it is driven by an AC source with source resistance of 10K.

5.

What happens to the gain of the circuit in Fig. (2.7) if it drives a load of 20K connected to the output.

6.

For the multi-stage amplifier circuit in Fig. 2.14. Let R₁=150K, R₂=15K, R_C = 20K,  R_E1=2K, R_E2=15K. Determine the values of the DC voltages V_C1, V_B1, V_E1, V_B2, V_E2, and V_C. What is the AC voltage gain? If a 20K load is attached to the output, what is the voltage gain?