Question

In an n-p-n common emitter (CE) transistor the collector current changes from 5 m A to 16 mA for the change in base current from 100 μ A and 200 μA , respectively. The current gain of transistor is Options 1. 110 2. 0.9 3. 210 4. 9

• A. 0.9
• B. 9
• C. 110
• D. 210

Answer 1

The Correct Option is C

Solution:
The current gain \( \beta \) for a common emitter transistor is given by the formula: \[ \beta = \frac{\Delta I_C}{\Delta I_B} \] Where:
\( \Delta I_C = 16 \text{ mA} - 5 \text{ mA} = 11 \text{ mA} \)
\( \Delta I_B = 200 \mu A - 100 \mu A = 100 \mu A \)

Now substitute the values:

\[ \beta = \frac{11 \text{ mA}}{100 \mu A} = \frac{11 \times 10^{-3}}{100 \times 10^{-6}} = 110 \] Thus, the current gain is \( \boxed{110} \).