Electrical Engineering (EE) Exam  >  Electrical Engineering (EE) Questions  >  What is the energy density spectrum of the si... Start Learning for Free
 What is the energy density spectrum of the signal x(n)=anu(n), |a|<1? 
  • a)
    1/(1+2acosω+a2 )
  • b)
    1/(1-2acosω+a2 )
  • c)
    1/(1-2acosω-a2 )
  • d)
    1/(1+2acosω-a2 )
Correct answer is option 'B'. Can you explain this answer?
Verified Answer
What is the energy density spectrum of the signal x(n)=anu(n), |a|<...
Given x(n)= anu(n), |a|<1 The auto correlation of the above signal is rxx(l)=1/(1-a2 ) a|l|, -8< l <8 According to Wiener-Khintchine Theorem, Sxx(?)=F{ rxx(l)}= [1/(1-a2)].F{a|l|} = 1/(1-2acos?+a2 )
View all questions of this test
Most Upvoted Answer
What is the energy density spectrum of the signal x(n)=anu(n), |a|<...
The energy density spectrum of the signal x(n) = anu(n) is:

E(f) = |a|^2/2πf, 0 < f="" />< />

where E(f) is the energy density at frequency f and u(n) is the unit step function.

To derive this, we first find the Fourier transform of x(n) as:

X(f) = ∑n=0^∞ anu(n) e^(-j2πfn)

= ∑n=0^∞ an e^(-j2πfn)

= a/(1 - e^(-j2πf))

Using Parseval's theorem, the energy in the signal can be calculated as:

E = (1/2π) ∫_-∞^∞ |X(f)|^2 df

= (1/2π) ∫_0^∞ |a|^2/(1 + 4π^2f^2) df

= |a|^2/2π ∫_0^∞ 1/(1 + (2πf)^2) df

= |a|^2/2

Therefore, the energy density at frequency f is given by:

E(f) = |X(f)|^2/2π

= |a|^2/(2π(1 + 4π^2f^2))

= |a|^2/2πf, 0 < f="" />< />

This result shows that the energy density spectrum of x(n) is a constant multiple of 1/f, which is a characteristic of a power-law spectrum.
Explore Courses for Electrical Engineering (EE) exam

Top Courses for Electrical Engineering (EE)

What is the energy density spectrum of the signal x(n)=anu(n), |a|<1?a)1/(1+2acosω+a2)b)1/(1-2acosω+a2)c)1/(1-2acosω-a2)d)1/(1+2acosω-a2)Correct answer is option 'B'. Can you explain this answer?
Question Description
What is the energy density spectrum of the signal x(n)=anu(n), |a|<1?a)1/(1+2acosω+a2)b)1/(1-2acosω+a2)c)1/(1-2acosω-a2)d)1/(1+2acosω-a2)Correct answer is option 'B'. Can you explain this answer? for Electrical Engineering (EE) 2024 is part of Electrical Engineering (EE) preparation. The Question and answers have been prepared according to the Electrical Engineering (EE) exam syllabus. Information about What is the energy density spectrum of the signal x(n)=anu(n), |a|<1?a)1/(1+2acosω+a2)b)1/(1-2acosω+a2)c)1/(1-2acosω-a2)d)1/(1+2acosω-a2)Correct answer is option 'B'. Can you explain this answer? covers all topics & solutions for Electrical Engineering (EE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for What is the energy density spectrum of the signal x(n)=anu(n), |a|<1?a)1/(1+2acosω+a2)b)1/(1-2acosω+a2)c)1/(1-2acosω-a2)d)1/(1+2acosω-a2)Correct answer is option 'B'. Can you explain this answer?.
Solutions for What is the energy density spectrum of the signal x(n)=anu(n), |a|<1?a)1/(1+2acosω+a2)b)1/(1-2acosω+a2)c)1/(1-2acosω-a2)d)1/(1+2acosω-a2)Correct answer is option 'B'. Can you explain this answer? in English & in Hindi are available as part of our courses for Electrical Engineering (EE). Download more important topics, notes, lectures and mock test series for Electrical Engineering (EE) Exam by signing up for free.
Here you can find the meaning of What is the energy density spectrum of the signal x(n)=anu(n), |a|<1?a)1/(1+2acosω+a2)b)1/(1-2acosω+a2)c)1/(1-2acosω-a2)d)1/(1+2acosω-a2)Correct answer is option 'B'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of What is the energy density spectrum of the signal x(n)=anu(n), |a|<1?a)1/(1+2acosω+a2)b)1/(1-2acosω+a2)c)1/(1-2acosω-a2)d)1/(1+2acosω-a2)Correct answer is option 'B'. Can you explain this answer?, a detailed solution for What is the energy density spectrum of the signal x(n)=anu(n), |a|<1?a)1/(1+2acosω+a2)b)1/(1-2acosω+a2)c)1/(1-2acosω-a2)d)1/(1+2acosω-a2)Correct answer is option 'B'. Can you explain this answer? has been provided alongside types of What is the energy density spectrum of the signal x(n)=anu(n), |a|<1?a)1/(1+2acosω+a2)b)1/(1-2acosω+a2)c)1/(1-2acosω-a2)d)1/(1+2acosω-a2)Correct answer is option 'B'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice What is the energy density spectrum of the signal x(n)=anu(n), |a|<1?a)1/(1+2acosω+a2)b)1/(1-2acosω+a2)c)1/(1-2acosω-a2)d)1/(1+2acosω-a2)Correct answer is option 'B'. Can you explain this answer? tests, examples and also practice Electrical Engineering (EE) tests.
Explore Courses for Electrical Engineering (EE) exam

Top Courses for Electrical Engineering (EE)

Explore Courses
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev