Question 145: Semiconductors and Logic Gates

Question

An n-p-n transistor operates as a common emitter
amplifier, with a power gain of 60 dB. The input
circuit resistance is 100$$\Omega $$ and the output load
resistance is 10 k$$\Omega $$. The common emitter
current gain $$\beta $$ is :

Accepted Answer

$${A_v} 	imes \beta  = {P_{gain}}$$
$$60 = 10{\log _{10}}\left( {{P \over {{P_0}}}} ight)$$
$$P = {10^6} = {\beta ^2} 	imes {{{R_{out}}} \over {{R_{in}}}}$$
$$ = {\beta ^2} 	imes {{{{10}^4}} \over {100}}$$
$${\beta ^2} = {10^4};\beta  = 100$$

Answer

10
4

Answer

10
2

Answer

6 × 10
2

Answer

60

Semiconductors and Logic Gates

An n-p-n transistor operates as a common emitter amplifier, with a power gain of 60 dB. The input circuit resistance is 100$\Omega and the output load resistance is 10 k\Omega . The common emitter current gain \beta $ is :

Choose the correct answer: