Q. In a common-emitter amplifier, the load resistance of the output circuit is 1000 times the resistance of the input circuit. If $\alpha = 0.98,$ then voltage gain is
A) ${49 \times 10}^{3}$
B) ${2.5 \times 10}^{2}$
C) ${1.5 \times 10}^{2}$
D) 4.9
Explanation
(a) Given, $\ \ \ \ \ \ \ \ \ \ \beta = \frac{\alpha}{1 - \alpha} = \frac{0.98}{1 - 0.98} = 49$
$\therefore$ Voltage gain = $\beta\frac{R_{2}}{R_{1}} = 49 \times 1000 = {49 \times 10}^{3}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.