Question

An npn transistor operates as a common emitter amplifier with a power gain of 10⁶. The input circuit resistance is 100 Ω and the output load resistance is 10 kΩ. The common emitter current gain 'β' will be __________. (Round off to the Nearest Integer)

Hint:

In a Common Emitter (CE) amplifier, Power Gain is the product of Voltage Gain and Current Gain ($\beta$).

Answer 1

Correct Answer: 100

Step 1: Power Gain ($P_{gain}$) = (Current Gain)² $\times$ Resistance Gain. $P_{gain} = \beta^2 \times \frac{R_{out}}{R_{in}}$.
Step 2: Substitute the values: $10^6 = \beta^2 \times \frac{10,000}{100} = \beta^2 \times 100$.
Step 3: $\beta^2 = \frac{10^6}{100} = 10^4 \implies \beta = \sqrt{10^4} = 100$.