Question

For a triode $r_{p} = 10$kilo ohm and $g_{m} = 3$milli mho. If the load resistance is double of plate resistance, then the value of voltage gain will be.

• A. 10
• B. 20
• C. 15
• D. 30

Answer 1

Answer: (B)

20

Answer 2

Voltage gain

$A_{V} = \frac{\mu}{1 + \frac{r_{p}}{R_{L}}}$and $\mu = r_{p} \times g_{m}$

$\Rightarrow \mu = 10 \times 10^{3} \times 3 \times 10^{- 3} = 30$

$\therefore A_{v} = \frac{\mu}{1 + \frac{r_{p}}{2r_{p}}} = \frac{2}{3}\mu = \frac{2}{3} \times 30 = 20.$