How to practice Random processes

Attempt a question, record the concept and assumptions, then check the available answer. Rework mistakes after revising the relevant concepts. Topic tags can overlap; review the question context.

Questions 1–10 of 14. Imported answers require independent review unless marked reviewed.

Topic practice 14 questionsPage 1 of 2

Question 42

Open question
ECMCQ2 marksNeeds review
Consider a real-valued random process

where

and

is a positive integer. Here,

for

and 0 otherwise. The coefficients

are pairwise independent, zero-mean unit-variance random variables.
Read the following statements about the random process and choose the correct option.
(i) The mean of the process

is independent of time

.
(ii) The autocorrelation function

is independent of time

for all

.
(Here,

is the expectation operation.)
Your answerChoose one option.

Log in to check the answer

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Question 20

Open question
ECMCQ1 markNeeds review
A white Gaussian noise

with zero mean and power spectral density

, when applied to a first-order RC low pass filter produces an output

. At a particular time

, the variance of the random variable

is ______.
Your answerChoose one option.

Log in to check the answer

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Question 57

Open question
ECNAT2 marksNeeds review
Let

be a random process, where amplitude

and phase

are independent of each other, and are uniformly distributed in the intervals

and

, respectively.

is fed to an 8-bit uniform mid-rise type quantizer. Given that the autocorrelation of

is

, the signal to quantization noise ratio (in dB, rounded off to two decimal places) at the output of the quantizer is __________.

Log in to check the answer

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Question 30

Open question
ECMSQ1 markNeeds review
For a real signal, which of the following is/are valid power spectral density/densities?
Your answerSelect all correct options. You can choose more than one.

Log in to check the answer

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Question 59

Open question
ECNAT2 marksNeeds review
Let

be a white Gaussian noise with power spectral density

W/Hz. If

is input to an LTI system with impulse response

. The average power of the system output is ________ W (rounded off to two decimal places).

Log in to check the answer

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Question 23

Open question
ECMCQ1 markNeeds review
The frequency response

of a linear time-invariant system has magnitude as shown in the figure.
Statement I: The system is necessarily a pure delay system for inputs which are bandlimited to

.
Statement II: For any wide-sense stationary input process with power spectral density

, the output power spectral density

obeys

for

.
Which one of the following combinations is true?
Diagram for Electronics and Communication Engineering question 23

Your answerChoose one option.

Log in to check the answer

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Question 48

Open question
ECMSQ2 marksNeeds review
A state transition diagram with states

,

, and

, and transition probabilities

is shown in the figure (e.g.,

denotes the probability of transition from state A to B). For this state diagram, select the state(s) which is/are universally true.
Diagram for Electronics and Communication Engineering question 48

Your answerSelect all correct options. You can choose more than one.

Log in to check the answer

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Question 21

Open question
ECNAT1 markNeeds review
The autocorrelation function

of a wide-sense stationary random process

is shown in the figure. The average power of

is ______.
Diagram for Electronics and Communication Engineering question 21


Log in to check the answer

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Question 24

Open question
ECNAT1 markNeeds review
The random variable

and

is a real white Gaussian noise process with two-sided power spectral density

W/Hz, for all

. The variance of Y is ______.

Log in to check the answer

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Question 45

Open question
ECNAT2 marksNeeds review
Let a random process

be described as

, where

is a white noise process with power spectral density

. The filter

has a magnitude response given by

for

, and zero elsewhere.

is a stationary random process, uncorrelated with

, with power spectral density as shown in the figure. The power in

, in watts, is equal to ______ W (rounded off to two decimal places).
Diagram for Electronics and Communication Engineering question 45


Log in to check the answer

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer