The GATE Grind

GATE 2024 IN – Question 27

Signals and Systems · Fourier analysis and sampling · 1 mark · Numerical answer

The Nyquist sampling frequency for $x(t)=10\sin^2(200\pi t)$ is ______ Hz (nearest integer).

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: 400 to 400

Explanation

Using $\sin^2\theta=(1-\cos2\theta)/2$ gives $x(t)=5-5\cos(400\pi t)$. The highest frequency is $400\pi/(2\pi)=200$ Hz. Twice this is the Nyquist rate: **400 Hz**.