Question

The minimum sampling frequency of signal ${10}^{2}sin{c}^3\left(200t\right)\ast 9sin{c}^2\left(600t\right)$ to avoid aliasing should be _____Hz.

• A. 600

Answer 1

The correct option is A 600
$x\left(t\right)={10}^{2}sin{c}^2\left(200t\right)\ast 9sin{c}^2\left(600t\right)$

Maximum frequency component present in ${10}^2$ $sin{c}^3\left(200t\right)$ is $600\pi rad/sec$. Maximum frequency component present in $9sin{c}^2\left(600t\right)$ is 1200$\pi$ rad/ sec.

Maximum frequency component present in ${10}^{2}sin{c}^3\left(200t\right)\ast 9sin{c}^2\left(600t\right)is600\pi rad/sec$ or 300 Hz

$\therefore$ Minimum sampling frequency = 2$\times$300 Hz = 600 Hz.