wayground logo

Free Printable Worksheets

Font size

S
M
L
XL
Worksheets

Exponential F.S. + GIBBS + Parseval's

Total questions: 11

Worksheet time: 6mins

Name
Class
Date
1.

Defining Cn=An2ejΘnC_n=\frac{A_n}{2}e^{j\Theta_n} for n > 0 leads to the synthesis equation x(t)=n=Cnejnw0tx\left(t\right)=\sum_{n=-\infty}^{\infty}C_ne^{jnw_0t} . What is the role of Cn in this representation?

a)

Complex Fourier coefficients capturing magnitude and phase

b)

Real-valued amplitudes scaling cosine harmonics only

c)

Time-domain weights varying with t for each harmonic

d)

Indices marking harmonic order without numerical value

2.

Which conclusion about energy distribution can be inferred from the 1/n magnitude decay of Cn?

a)

Higher harmonics dominate energy

b)

Lower harmonics dominate energy

c)

Energy is concentrated at even indices

d)

Energy is uniform across harmonics

3.

Which property makes the rectified sine wave periodic with T = π rather than 2π?

a)

It repeats every half sine due to rectification

b)

Its amplitude doubles every half period

c)

Its phase resets only after 2π

d)

It contains only odd symmetry

4.

From x(t)=2Aπ+2Aπn=(ej2nt14n2)x\left(t\right)=\frac{2A}{\pi}+\frac{2A}{\pi}\sum_{n=-\infty}^{\infty}\left(\frac{e^{j2nt}}{1-4n^2}\right) , what does the term 2Aπ\frac{2A}{\pi} represent?

a)

DC component of the signal

b)

Fundamental cosine term

c)

Quadrature sine term

d)

Spectral leakage term

5.

Why do the Fourier coefficients Cn form a discrete spectrum?

a)

Coefficients exist only for discrete n

b)

Coefficients depend on nonperiodic time

c)

Coefficients vary continuously in frequency

d)

Coefficients exist only for continuous ω

6.

For a complex spectrum of Cn, which spectra are typically plotted?

a)

Magnitude and phase spectra

b)

Time and frequency spectra

c)

Energy and power spectra

d)

Real and imaginary spectra

7.

Using Euler’s identity, ejnw0te^{jnw_0t} equals which trigonometric combination?

a)

cos(nw0t)+jsin(nw0t)\cos\left(nw_0t\right)+j\sin\left(nw_0t\right)

b)

cos(nw0t)jsin(nw0t)\cos\left(nw_0t\right)-j\sin\left(nw_0t\right)

c)

sin(nw0t)+jcos(nw0t)\sin\left(nw_0t\right)+j\cos\left(nw_0t\right)

d)

sin(nw0t)jcos(nw0t)\sin\left(nw_0t\right)-j\cos\left(nw_0t\right)

8.

Which formula correctly converts the DC term between forms?

a)


C0 equals a0

b)

C0 equals b0

c)

a0 equals jC0

d)

a0 equals 2C0

9.

In the diagram, the oscillatory ripples near the vertical dashed line are labeled as the Gibbs phenomenon. What feature of the signal causes these ripples to appear during Fourier series reconstruction?

a)

Smooth slope transitions in the waveform

b)

Finite energy of the periodic signal components

c)


Discontinuities producing abrupt amplitude jumps

d)

Low-frequency content dominating the spectrum

10.

As more harmonics are added to a truncated Fourier series of a square-like wave, what change is observed near the edges?

a)

Overshoots broaden with larger amplitude

b)


Overshoots get sharper with reduced adjoining amplitude

c)

Overshoots disappear completely at high harmonics

d)

Edges blur due to increased low-frequency content

11.

What is the primary physical interpretation of Parseval’s identity for periodic signals?

a)


Energy conservation between time and frequency domains

b)

Phase synchronization of harmonics across cycles

c)

Amplitude normalization of the fundamental component

d)

Noise suppression by complex conjugation