In a common base configuration, the transistor has emitter current of 10 mA and collector current of 9.8 mA. The value of base current is….

Options

A. 0.1 mA
B. 0.2 mA
C. 0.3 mA
D. 0.4 mA

Answer

To find the base current (IB) in a common base configuration of a transistor, we can use the relationship between the emitter current (IE), collector current (IC), and base current (IB). The fundamental equation governing these currents in a transistor is:

\[ I_E = I_B + I_C \]

Where:
- \( I_E \) is the emitter current
- \( I_B \) is the base current
- \( I_C \) is the collector current

Given:
- \( I_E = 10 \, \text{mA} \)
- \( I_C = 9.8 \, \text{mA} \)

We can rearrange the equation to solve for the base current \( I_B \):

1. Start with the equation:
\[ I_E = I_B + I_C \]

2. Substitute the known values into the equation:
\[ 10 \, \text{mA} = I_B + 9.8 \, \text{mA} \]

3. Rearrange the equation to isolate \( I_B \):
\[ I_B = I_E - I_C \]

4. Substitute the values:
\[ I_B = 10 \, \text{mA} - 9.8 \, \text{mA} \]

5. Calculate \( I_B \):
\[ I_B = 0.2 \, \text{mA} \]

Thus, the value of the base current \( I_B \) is **0.2 mA**.