Question

In a transistor amplifier $\beta = 62$,${R_L} = 5000\Omega$ and internal resistance of the transistor is $500\Omega$. Its power amplification will be
A)$\;25580$
B) $33760$
C) $38440$
D) $55760$

Answer 1

The transistor is a semiconductor device used for amplifying the electric signals and the power. The transistor has three terminals called the emitter, base, and collector. The small change in the input signal causes more emitter current than the voltage applied. This emitter current can be drawn from the collector through the load resistance.

Formula used:
${R_g} = \dfrac{{{R_L}}}{{{R_I}}}$
Where,
${R_g}$- Resistance gain
${R_L}$- Load resistance
${R_I}$- Input resistance

Complete step by step answer:
To know the power amplification of the transistor amplifier, we need to know the current and the resistance gain. The current gain $\beta$ is given as 62.
The resistance gain,
${R_g} = \dfrac{{{R_L}}}{{{R_I}}}$
When we divide the load resistance by the resistor current, we get the value of the resistance gain,
Applying the given values in the formula,
We can use the arithmetic division to divide the values,
$\Rightarrow {R_g} = \dfrac{{5000}}{{500}}$
By doing the simplifications we get,
$\Rightarrow {R_g} = 10$
The power amplification is nothing but the power gain at the output. The power gain can be found by power equation,
$\Rightarrow P = {I^2}R$
This equation can be modified as,
Power amplification =${\left( {{\text{current gain}}} \right)^{\text{2}}}{{ \times} \text{ resistance}}$
We can use the arithmetic multiplications to multiply the given values and then we can substitute the values in then given equations,
$\Rightarrow {(62)^2} \times 10$
$\therefore$ Power amplification = $38440$

Hence the correct option is C.

Note:
The transistor is the three-terminal semiconductor device that is used to amplify the power of the output and also used to amplify the current. Hence the transistor is also an amplifier. The transistor amplifier circuit is used in long-distance communication applications such as radio communication and optical communication and wherever the high output is required.