A transistor is connected in common emmitter `(CE)` configuration. The collector supply is `8V` and the voltage deop across a resistor of `800 Omega` in the collector circuit is `0.8 V`. If the current gain factor `(alpha)` is `0.96`, then the change in base current is

Options

A. `1/24 mA`
B. `1/12 mA`
C. `1/6mA`
D. `1/3mA`

Answer

To solve the problem step by step, we will follow the outlined approach in the video transcript.

### Step 1: Identify the given values
- Collector supply voltage (V_C) = 8V
- Voltage drop across the collector resistor (V_R) = 0.8V
- Collector resistor (R_C) = 800Ω
- Current gain factor (α) = 0.96

### Step 2: Calculate the collector current (I_C)
The collector current (I_C) can be calculated using Ohm's law:
\[ I_C = \frac{V_R}{R_C} \]

Substituting the known values:
\[ I_C = \frac{0.8V}{800Ω} \]
\[ I_C = 0.001A = 1mA \]

### Step 3: Calculate the current gain factor (β)
The relationship between α and β is given by:
\[ \beta = \frac{\alpha}{1 - \alpha} \]

Substituting the value of α:
\[ \beta = \frac{0.96}{1 - 0.96} \]
\[ \beta = \frac{0.96}{0.04} \]
\[ \beta = 24 \]

### Step 4: Calculate the base current (I_B)
The base current (I_B) can be calculated using the relationship:
\[ I_B = \frac{I_C}{\beta} \]

Substituting the known values:
\[ I_B = \frac{1mA}{24} \]
\[ I_B = \frac{1}{24} mA \]

### Step 5: Conclusion
The change in base current (ΔI_B) is:
\[ ΔI_B = \frac{1}{24} mA \]

### Final Answer
The change in base current is \( \frac{1}{24} mA \).

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