Condition For Existence of Fourier Transform MCQ Quiz - Objective Question with Answer for Condition For Existence of Fourier Transform - Download Free PDF
Last updated on May 30, 2025
Latest Condition For Existence of Fourier Transform MCQ Objective Questions
Condition For Existence of Fourier Transform Question 1:
The Fourier Transform of an real and even function results in:
Answer (Detailed Solution Below)
Condition For Existence of Fourier Transform Question 1 Detailed Solution
Concept: Fourier Transform Symmetry Property
If a time-domain function f(t) is:
-
Real: It has no imaginary part
-
Even: f(t) = f(-t)" id="MathJax-Element-103-Frame" role="presentation" style="position: relative;" tabindex="0">
f(t) = f(-t)" id="MathJax-Element-1-Frame" role="presentation" style="position: relative;" tabindex="0"> f(t) = f(-t) f(t)=f(−t)
Then it's Fourier Transform " id="MathJax-Element-104-Frame" role="presentation" style="position: relative;" tabindex="0">
-
Purely real
-
Even: F(ω)=F(−ω)" id="MathJax-Element-105-Frame" role="presentation" style="position: relative;" tabindex="0">
" id="MathJax-Element-3-Frame" role="presentation" style="position: relative;" tabindex="0">
🔍 Example: Cosine Wave
Let’s take: f(t) = cos(ω0t)
-
It is real.
-
It is even, because " id="MathJax-Element-107-Frame" role="presentation" style="position: relative;" tabindex="0">
" id="MathJax-Element-4-Frame" role="presentation" style="position: relative;" tabindex="0"> cos(−ω0t)=cos(ω0t)
Fourier Transform of " id="MathJax-Element-108-Frame" role="presentation" style="position: relative;" tabindex="0">
This result is:
-
Purely real (involves delta functions, no imaginary component)
-
Even since it's symmetric around " id="MathJax-Element-109-Frame" role="presentation" style="position: relative;" tabindex="0">
" id="MathJax-Element-6-Frame" role="presentation" style="position: relative;" tabindex="0"> ω=0
Condition For Existence of Fourier Transform Question 2:
A signal x(t) has a fourier transform x(ω). If x(t) is a real and even function the x(ω) is Even
Answer (Detailed Solution Below)
Condition For Existence of Fourier Transform Question 2 Detailed Solution
x(t) – x(ω) pairs
X(t) |
X(ω) |
R |
C.S |
C.S |
R |
I |
C.A.S |
C.A.S |
I |
R + E |
R + E |
R + O |
I + O |
I + E |
I + E |
I + O |
R + 0 |
R → Real, C.S → Conjugate Symmetry.
I – Imaginary, CAS → Conjugate Any Symmetry
E → Even, O → Odd
Top Condition For Existence of Fourier Transform MCQ Objective Questions
The Fourier Transform of an real and even function results in:
Answer (Detailed Solution Below)
Condition For Existence of Fourier Transform Question 3 Detailed Solution
Download Solution PDFConcept: Fourier Transform Symmetry Property
If a time-domain function f(t) is:
-
Real: It has no imaginary part
-
Even: f(t) = f(-t)" id="MathJax-Element-103-Frame" role="presentation" style="position: relative;" tabindex="0">
f(t) = f(-t)" id="MathJax-Element-1-Frame" role="presentation" style="position: relative;" tabindex="0"> f(t) = f(-t) f(t)=f(−t)
Then it's Fourier Transform " id="MathJax-Element-104-Frame" role="presentation" style="position: relative;" tabindex="0">
-
Purely real
-
Even: F(ω)=F(−ω)" id="MathJax-Element-105-Frame" role="presentation" style="position: relative;" tabindex="0">
" id="MathJax-Element-3-Frame" role="presentation" style="position: relative;" tabindex="0">
🔍 Example: Cosine Wave
Let’s take: f(t) = cos(ω0t)
-
It is real.
-
It is even, because " id="MathJax-Element-107-Frame" role="presentation" style="position: relative;" tabindex="0">
" id="MathJax-Element-4-Frame" role="presentation" style="position: relative;" tabindex="0"> cos(−ω0t)=cos(ω0t)
Fourier Transform of " id="MathJax-Element-108-Frame" role="presentation" style="position: relative;" tabindex="0">
This result is:
-
Purely real (involves delta functions, no imaginary component)
-
Even since it's symmetric around " id="MathJax-Element-109-Frame" role="presentation" style="position: relative;" tabindex="0">
" id="MathJax-Element-6-Frame" role="presentation" style="position: relative;" tabindex="0"> ω=0
Condition For Existence of Fourier Transform Question 4:
A signal x(t) has a fourier transform x(ω). If x(t) is a real and even function the x(ω) is Even
Answer (Detailed Solution Below)
Condition For Existence of Fourier Transform Question 4 Detailed Solution
x(t) – x(ω) pairs
X(t) |
X(ω) |
R |
C.S |
C.S |
R |
I |
C.A.S |
C.A.S |
I |
R + E |
R + E |
R + O |
I + O |
I + E |
I + E |
I + O |
R + 0 |
R → Real, C.S → Conjugate Symmetry.
I – Imaginary, CAS → Conjugate Any Symmetry
E → Even, O → Odd
Condition For Existence of Fourier Transform Question 5:
The Fourier Transform of an real and even function results in:
Answer (Detailed Solution Below)
Condition For Existence of Fourier Transform Question 5 Detailed Solution
Concept: Fourier Transform Symmetry Property
If a time-domain function f(t) is:
-
Real: It has no imaginary part
-
Even: f(t) = f(-t)" id="MathJax-Element-103-Frame" role="presentation" style="position: relative;" tabindex="0">
f(t) = f(-t)" id="MathJax-Element-1-Frame" role="presentation" style="position: relative;" tabindex="0"> f(t) = f(-t) f(t)=f(−t)
Then it's Fourier Transform " id="MathJax-Element-104-Frame" role="presentation" style="position: relative;" tabindex="0">
-
Purely real
-
Even: F(ω)=F(−ω)" id="MathJax-Element-105-Frame" role="presentation" style="position: relative;" tabindex="0">
" id="MathJax-Element-3-Frame" role="presentation" style="position: relative;" tabindex="0">
🔍 Example: Cosine Wave
Let’s take: f(t) = cos(ω0t)
-
It is real.
-
It is even, because " id="MathJax-Element-107-Frame" role="presentation" style="position: relative;" tabindex="0">
" id="MathJax-Element-4-Frame" role="presentation" style="position: relative;" tabindex="0"> cos(−ω0t)=cos(ω0t)
Fourier Transform of " id="MathJax-Element-108-Frame" role="presentation" style="position: relative;" tabindex="0">
This result is:
-
Purely real (involves delta functions, no imaginary component)
-
Even since it's symmetric around " id="MathJax-Element-109-Frame" role="presentation" style="position: relative;" tabindex="0">
" id="MathJax-Element-6-Frame" role="presentation" style="position: relative;" tabindex="0"> ω=0
Condition For Existence of Fourier Transform Question 6:
A signal x(t) has a fourier transform x(ω). If x(t) is a real and even function the x(ω) is Even
Answer (Detailed Solution Below)
Condition For Existence of Fourier Transform Question 6 Detailed Solution
x(t) – x(ω) pairs
X(t) |
X(ω) |
R |
C.S |
C.S |
R |
I |
C.A.S |
C.A.S |
I |
R + E |
R + E |
R + O |
I + O |
I + E |
I + E |
I + O |
R + 0 |
R → Real, C.S → Conjugate Symmetry.
I – Imaginary, CAS → Conjugate Any Symmetry
E → Even, O → Odd
Condition For Existence of Fourier Transform Question 7:
Consider the single x[n] = 2n u[n]. The given signal does not coverage. To make the signal converge. The signal is multiplied by r-n i.e. now the modified signal is x’[n] = r-n x[n]. The range of r for which the signal will converge is
Answer (Detailed Solution Below)
Condition For Existence of Fourier Transform Question 7 Detailed Solution
For convergence the signal should be absolutely summable.
Therefore, the Fourier transform of r-n x[n] converges for |r| > 2
Condition For Existence of Fourier Transform Question 8:
For the given signal f(t), what is the amplitude of Fourier transform of f(t)?
Answer (Detailed Solution Below)
Condition For Existence of Fourier Transform Question 8 Detailed Solution
we know that Fourier transform of pulse is a sampling function
If F(ω) is the Fourier transform, then
A → Amplitude
τ → pulse width
Amplitude of sampling function = Area of pulse in time domain
= 10 × {10 - (- 5)}
= 150