The emitter current in a transistor is 2.2mA and the collector current is 2mA. The base current is

Options

A. `100 mu A `
B. `200 mu A`
C. `300 mu A `
D. `400 mu A `

Answer

To find the base current (IB) in a transistor, we can use the relationship between the emitter current (IE), collector current (IC), and base current (IB). The relationship is given by the equation:

\[ I_E = I_B + I_C \]

### Step-by-step Solution:

1. **Identify the given values:**
- Emitter current (IE) = 2.2 mA
- Collector current (IC) = 2 mA

2. **Convert the currents to the same unit (if necessary):**
- Since both currents are given in milliampere (mA), we can directly use them in the equation.
- IE = 2.2 mA = 2.2 × 10^-3 A
- IC = 2 mA = 2 × 10^-3 A

3. **Use the formula to find the base current (IB):**
\[ I_B = I_E - I_C \]

4. **Substitute the known values into the equation:**
\[ I_B = 2.2 \text{ mA} - 2 \text{ mA} \]

5. **Calculate IB:**
\[ I_B = 0.2 \text{ mA} \]

6. **Convert IB to microamperes (µA):**
- Since 1 mA = 1000 µA, we can convert:
\[ I_B = 0.2 \text{ mA} \times 1000 \text{ µA/mA} = 200 \text{ µA} \]

### Final Answer:
The base current (IB) is **200 µA**.