Q. The transconductance of a triode amplifier is $2.5\ mili\ mho$ having plate resistance of $20\ k\Omega$, amplification 10. Find the load resistance
A) $5\ k\Omega$
B) $25\ k\Omega$
C) $20\ k\Omega$
D) $50\ k\Omega$
Explanation
(a) Voltage amplification $A_{v} = \frac{\mu}{1 + \frac{r_{p}}{R_{L}}} = \frac{r_{p} \times g_{m} \times R_{L}}{R_{L} + r_{p}}$
$\Rightarrow 10 = \frac{20 \times 10^{3} \times 2.5 \times 10^{- 3} \times R_{L}}{(R_{L} + 20 \times 10^{3})} \Rightarrow R_{L} = 5k\Omega$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.