In a transistor circuit, when the base current is increased by '100 mu A', keeping the collector voltage fixed at 2V, the collector current increases by 1mA. The current gain of the transistot is

Options

A. 20
B. 40
C. 60
D. 80

Answer

To find the current gain of the transistor, we can follow these steps:

### Step 1: Identify the given values
- Change in base current (ΔIB) = 100 µA = 100 × 10^(-6) A
- Change in collector current (ΔIC) = 1 mA = 1 × 10^(-3) A

### Step 2: Write the formula for current gain (β)
The current gain (β) of a transistor is defined as the ratio of the change in collector current to the change in base current. The formula is:
\[ \beta = \frac{\Delta IC}{\Delta IB} \]

### Step 3: Substitute the values into the formula
Now, substituting the values we have:
\[ \beta = \frac{1 \times 10^{-3} \text{ A}}{100 \times 10^{-6} \text{ A}} \]

### Step 4: Simplify the expression
To simplify:
\[ \beta = \frac{1 \times 10^{-3}}{100 \times 10^{-6}} = \frac{1 \times 10^{-3}}{1 \times 10^{-4}} = \frac{1}{0.1} = 10 \]

### Step 5: State the final answer
Thus, the current gain (β) of the transistor is:
\[ \beta = 10 \]