MCQ
In the following common emitter configuration an $NPN $ transistor with current gain $\beta$ $= 100$ is used. The output voltage of the amplifier will be
- A$10\, mV$
- B$0.1 \,V$
- ✓$1.0 \,V$
- D$10\, V$
✓
Answer
Correct option: C.
$1.0 \,V$
c
(c)Voltage gain $ = \frac{{{\rm{Output voltage}}}}{{{\rm{Input voltage}}}}$
$⇒ V_{out} = V_{in} ×$ Voltage gain
$⇒$$ V_{out} = V_{in} ×$ Current gain $×$ Resistance gain
$= V_{in} ×\beta × \frac{{{R_L}}}{{{R_{BE}}}}$= ${10^{ - 3}} \times 100 \times \frac{{10}}{1} = 1V.$
(c)Voltage gain $ = \frac{{{\rm{Output voltage}}}}{{{\rm{Input voltage}}}}$
$⇒ V_{out} = V_{in} ×$ Voltage gain
$⇒$$ V_{out} = V_{in} ×$ Current gain $×$ Resistance gain
$= V_{in} ×\beta × \frac{{{R_L}}}{{{R_{BE}}}}$= ${10^{ - 3}} \times 100 \times \frac{{10}}{1} = 1V.$
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