Question

A periodic rectangular signal X (t) has the waveform as shown below. The frequency of the fifth harmonic of its spectrum is ______________

(a) 40 Hz

(b) 200 Hz

(c) 250 Hz

(d) 1250 Hz

I have been asked this question during an online exam.

My doubt stems from Problems Involving Standard Time Functions topic in section Application of the Laplace Transform in Circuit Analysis of Network Theory

Answer 1

Correct answer is (d) 1250 Hz

Explanation: Periodic time = 4 ms = 4 × 10^-3

Fundamental frequency = \(\frac{10^3}{4}\) = 250 Hz

∴ Frequency of the fifth harmonic = 250 × 5 = 1250 Hz.