Semiconductor Electronics Materials Devices and Simple Circuits - Result Question 62
64. The input signal given to a $CE$ amplifier having a voltage gain of 150 is $V_i=2 \cos (15 t+\frac{\pi}{3})$.
The corresponding output signal will be :
[2015 RS]
(a) $75 \cos (15 t+\frac{2 \pi}{3})$
(b) $2 \cos (15 t+\frac{5 \pi}{6})$
(c) $300 \cos (15 t+\frac{4 \pi}{3})$
(d) $300 \cos (15 t+\frac{\pi}{3})$
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Answer:
Correct Answer: 64. (c)
Solution:
- (c) Given : Voltage gain $A_V=150$
$V_i=2 \cos (15 t+\frac{\pi}{3}) ; V_0=$ ?
For CE transistor phase difference between input and output signal is $\pi=180^{\circ}$
Using formula, $A_V=\frac{V_0}{V_i}$
$\Rightarrow V_0=A_V \times V_i$
$=150 \times 2 \cos (15 t+\frac{\pi}{3})$
or $V_0=300 \cos (15 t+\frac{\pi}{3}+\pi)$
$V_0=300 \cos (15 t+\frac{4}{3} \pi)$
