Question

A waveform is given by v(t) = 10 sin2π 100 t. The magnitude of the second harmonic in its Fourier series representation is ____________

(a) 0 V

(b) 20 V

(c) 100 V

(d) 200 V

The question was asked by my college director while I was bunking the class.

Question is from Trigonometric Fourier Series in portion Fourier Series of Signals and Systems

Answer 1

Correct option is (a) 0 V

For explanation I would say: Given that v (t) = 10 sin2π 100 t

It holds the half-wave symmetry i.e. x (t) = -x (t ± \(\frac{T}{2}\))

And for half wave symmetry, a0 = 0 and ak = 0 (k is even)

So, second harmonic component a2 = 0.