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If G(f) represents the Fourier transform of a signal g(t) which is real and odd symmetric in time, then

A. G(f) is complex

B. G(f) is imaginary

C. G(f) is real

D. G(f) is real and non-negative

Answer: Option B

Solution (By Examveda Team)

Okay, let's break down this Fourier Transform question for beginners!

The question is asking what happens to the Fourier Transform (G(f)) of a signal g(t), when that signal is both real and odd-symmetric.

Let's define each part:
* Fourier Transform: Think of it as a way to see what frequencies make up a signal. It transforms a signal from the time domain (how it changes over time) to the frequency domain (how much of each frequency is present).
* Real Signal: A signal is real if its values are real numbers (no imaginary part). Most signals we deal with in the real world are real (e.g., sound waves, voltage).
* Odd Symmetry: A signal g(t) is odd-symmetric if g(-t) = -g(t). This means if you flip the signal around the y-axis and then flip it around the x-axis, you get the same signal back. A simple example is g(t) = t.

Now, here's the key concept:
The Fourier Transform has some properties related to symmetry.

Important Relationship: When g(t) is real and odd, its Fourier Transform G(f) will be purely imaginary.

Let's look at why the other options are incorrect.
* Option A: G(f) is complex: While *any* Fourier Transform *can* be complex, the combination of real and odd symmetry *simplifies* it.
* Option C: G(f) is real: A real and even signal in the time domain would give a real fourier transform.
* Option D: G(f) is real and non-negative: A real and non-negative time-domain signal doesn't guarantee the same characteristics in the frequency domain.

Therefore, the answer is Option B: G(f) is imaginary.

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Comments (1)

  1. Vinayak Medar
    Vinayak Medar:
    6 months ago

    wrong ans correct b

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