Electronic Devices Question 209
Question: Plate resistance of two triode valves is 2 KW and 4 KW, amplification factor of each of the valves is 40. The ratio of voltage amplification, when used with 4 KW load resistance, will be
[RPET 1998]
Options:
A) 10
B) $ \frac{4}{3} $
C) $ \frac{3}{4} $
D) $ \frac{16}{3} $
Show Answer
Answer:
Correct Answer: C
Solution:
Voltage amplification $ A _{V}=\frac{\mu }{1+\frac{r _{p}}{R _{L}}}=\frac{\mu R _{L}}{R _{L}+r _{p}} $
$ \Rightarrow \frac{A _{1}}{A _{2}}=\frac{2+4}{4+4}=\frac{3}{4} $ .
