Semiconductor Electronics Materials Devices and Simple Circuits - Result Question 73

75. A transistor is operated in common emitter configuration at constant collector voltage $V_c=$ $1.5 V$ such that a change in the base current from $100 \mu A$ to $150 \mu A$ produces a change in the collector current from $5 mA$ to $10 mA$. The current gain $(\beta)$ is

[2006]

(a) 75

(b) 100

(c) 50

(d) 67

Show Answer

Answer:

Correct Answer: 75. (b)

Solution:

$ \begin{aligned} & \text{ (b) } \Delta I_b=+50 \mu A, \Delta I_c=5 \times 10^{-3} A \\ & \beta=\frac{\Delta I_c}{\Delta I_b}=\frac{5 \times 10^{-3}}{50 \times 10^{-6}}=\frac{5 \times 1000}{50}=100 \end{aligned} $