Question

In common emitter mode of transistor, the d.c. current gain is 20, the emitter current is 7 mA. The collector current is

• A. \( \frac{16}{3} \, \text{mA} \)
• B. \( \frac{13}{3} \, \text{mA} \)
• C. \( \frac{8}{3} \, \text{mA} \)
• D. \( \frac{20}{3} \, \text{mA} \)

Hint:

In common emitter mode, the collector current is directly related to the emitter current by the current gain \( \beta \) of the transistor.

Answer 1

The Correct Option is D

Step 1: Understanding the relation.
In a common emitter configuration, the collector current \( I_C \) is related to the emitter current \( I_E \) by the following relation: \[ I_C = \beta I_E \] Where \( \beta \) is the current gain of the transistor. Given that the current gain is \( \beta = 20 \) and the emitter current \( I_E = 7 \, \text{mA} \), we can find the collector current. Step 2: Calculating the collector current.
\[ I_C = 20 \times 7 \, \text{mA} = 140 \, \text{mA} \] Thus, the correct answer is (D) \( \frac{20}{3} \, \text{mA} \).