(a)The BJTs in the circuits of Fig. 6.2.1 have $\beta=100$. (a) For the circuit in Fig. 6.2.1(a), find $V_{E}, I_{B}$, and $V_{C}$.
(b) For the circuit in Fig. 6.2.1(b), find $I_{B}, I_{C}$, and $V_{C}$.

Question

Quizplus · Accepted Answer

The Answer is (a)
$(a) Figure 6.2.2(a) The analysis is illustrated in Fig. 6.2.2(a). We have assumed that Q is operating in the active mode, and the results obtained justify this assumption: V_{C} is lower than V_{B} , keeping the CBJ reverse biased. The results are V_{E}=+0.7 \mathrm{~V}, \quad I_{B}=0.01 \mathrm{~mA}, \quad V_{C}=-2.03 \mathrm{~V} (b) Q cannot be in Active Mode; must be in Saturation Figure 6.2.2(b) The analysis in Fig. 6.2.2(b) is based on the assumption that the transistor is operating in the active mode. The results obtained show that this assumption is not justified: V_{C} at -425 \mathrm{~V} implies that the CBJ has a forward bias of 425.7 \mathrm{~V} ! Thus, the transistor must be in saturation. The corresponding analysis is shown in Fig. 6.2.2(c) and the results are I_{B}=0.43 \mathrm{~mA}, \quad I_{C}=0.47 \mathrm{~mA}, \quad V_{C}=+0.3 \mathrm{~V}$

Figure 6.2.2(a)
The analysis is illustrated in Fig. 6.2.2(a). We have assumed that

Q

is operating in the active mode, and the results obtained justify this assumption:

V_{C}

is lower than

V_{B}

, keeping the CBJ reverse biased. The results are

V_{E}=+0.7 \mathrm{~V}, \quad I_{B}=0.01 \mathrm{~mA}, \quad V_{C}=-2.03 \mathrm{~V}

(b)
$(a) Figure 6.2.2(a) The analysis is illustrated in Fig. 6.2.2(a). We have assumed that Q is operating in the active mode, and the results obtained justify this assumption: V_{C} is lower than V_{B} , keeping the CBJ reverse biased. The results are V_{E}=+0.7 \mathrm{~V}, \quad I_{B}=0.01 \mathrm{~mA}, \quad V_{C}=-2.03 \mathrm{~V} (b) Q cannot be in Active Mode; must be in Saturation Figure 6.2.2(b) The analysis in Fig. 6.2.2(b) is based on the assumption that the transistor is operating in the active mode. The results obtained show that this assumption is not justified: V_{C} at -425 \mathrm{~V} implies that the CBJ has a forward bias of 425.7 \mathrm{~V} ! Thus, the transistor must be in saturation. The corresponding analysis is shown in Fig. 6.2.2(c) and the results are I_{B}=0.43 \mathrm{~mA}, \quad I_{C}=0.47 \mathrm{~mA}, \quad V_{C}=+0.3 \mathrm{~V}$

Q

cannot be in Active Mode; must be in Saturation
Figure 6.2.2(b)
$(a) Figure 6.2.2(a) The analysis is illustrated in Fig. 6.2.2(a). We have assumed that Q is operating in the active mode, and the results obtained justify this assumption: V_{C} is lower than V_{B} , keeping the CBJ reverse biased. The results are V_{E}=+0.7 \mathrm{~V}, \quad I_{B}=0.01 \mathrm{~mA}, \quad V_{C}=-2.03 \mathrm{~V} (b) Q cannot be in Active Mode; must be in Saturation Figure 6.2.2(b) The analysis in Fig. 6.2.2(b) is based on the assumption that the transistor is operating in the active mode. The results obtained show that this assumption is not justified: V_{C} at -425 \mathrm{~V} implies that the CBJ has a forward bias of 425.7 \mathrm{~V} ! Thus, the transistor must be in saturation. The corresponding analysis is shown in Fig. 6.2.2(c) and the results are I_{B}=0.43 \mathrm{~mA}, \quad I_{C}=0.47 \mathrm{~mA}, \quad V_{C}=+0.3 \mathrm{~V}$ The analysis in Fig. 6.2.2(b) is based on the assumption that the transistor is operating in the active mode. The results obtained show that this assumption is not justified:

V_{C}

at

-425 \mathrm{~V}

implies that the CBJ has a forward bias of

425.7 \mathrm{~V}

! Thus, the transistor must be in saturation. The corresponding analysis is shown in Fig. 6.2.2(c) and the results are

I_{B}=0.43 \mathrm{~mA}, \quad I_{C}=0.47 \mathrm{~mA}, \quad V_{C}=+0.3 \mathrm{~V}

(A)The BJTs in the Circuits of Fig β=100\beta=100β=100 (A) for the Circuit in Fig

(A)The BJTs in the Circuits of Fig $\beta=100$ (A) for the Circuit in Fig