Digital Signal Processing

Classification of Signals

Question 1
Marks : +2 | -2
Pass Ratio : 100%
The deflection voltage of an oscilloscope is a ‘deterministic’ signal.
True
False
Explanation:
The behavior of the signal is known and can be represented by a saw tooth wave form. So, the signal is deterministic.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Which of the following is done to convert a continuous time signal into discrete time signal?
Modulating
Sampling
Differentiating
Integrating
Explanation:
A discrete time signal can be obtained from a continuous time signal by replacing t by nT, where T is the reciprocal of the sampling rate or time interval between the adjacent values. This procedure is known as sampling.
Question 3
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Pass Ratio : 100%
What is the period of cos2t+sin3t?
pi
2*pi
3*pi
4*pi
Explanation:
Period of cos2t=(2*pi)/2=pi
Question 4
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Pass Ratio : 100%
Let x1(t) and x2(t) be periodic signals with fundamental periods T1 and T2 respectively. Which of the following must be a rational number for x(t)=x1(t)+x2(t) to be periodic?
T1+T2
T1-T2
T1/T2
T1*T2
Explanation:
Let T be the period of the signal x(t)
Question 5
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Pass Ratio : 100%
Which of the following is the odd component of the signal x(t)=e(jt)?
cost
j*sint
j*cost
sint
Explanation:
Let x(t)=e(jt)
Question 6
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Pass Ratio : 100%
x(t) or x(n) is defined to be an energy signal, if and only if the total energy content of the signal is a ___________
Finite quantity
Infinite
Zero
None of the mentioned
Explanation:
The energy signal should have a total energy value that lies between 0 and infinity.
Question 7
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Pass Ratio : 100%
For a continuous time signal x(t) to be periodic with a period T, then x(t+mT) should be equal to ___________
x(-t)
x(mT)
x(mt)
x(t)
Explanation:
If a signal x(t) is said to be periodic with period T, then x(t+mT)=x(t) for all t and any integer m.
Question 8
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The even part of a signal x(t) is?
x(t)+x(-t)
x(t)-x(-t)
(1/2)*(x(t)+x(-t))
(1/2)*(x(t)-x(-t))
Explanation:
Let x(t)=xe(t)+xo(t)
Question 9
Marks : +2 | -2
Pass Ratio : 100%
All energy signals will have an average power of ___________
Infinite
Zero
Positive
Cannot be calculated
Explanation:
For any energy signal, the average power should be equal to 0 i.e., P=0.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Let x1(t) and x2(t) be periodic signals with fundamental periods T1 and T2 respectively. Then the fundamental period of x(t)=x1(t)+x2(t) is?
LCM of T1 and T2
HCF of T1and T2
Product of T1 and T2
Ratio of T1 to T2
Explanation:
For the sum of x1(t) and x2(t) to be periodic the ratio of their periods should be a rational number, then the fundamental period is the LCM of T1 and T2.