A fresh set of 20 random questions is generated every time you open this page and every time you refresh it.For each of the following multiple choice questions, choose the most appropriate answer :
1. Which of the following is/are not a property/properties power spectral density function Sx(?)?
A. Sx(?) is real function of ?
B. Sx(?) is a even function of ?
C. Sx(?) is a odd function of ?
D. Sx(?) is non-positive function of ?Sx(?) ? 0 for all ?
2. A sine wave in the ______ domain can be represented by one single spike in the _____ domain.
A. time; frequency
B. frequency; time
C. time; phase
D. phase; time
3. A system is said to be defined as non causal, when
A. the output at the present depends on the input at an earlier time
B. the output at the present does not depend on the factor of time at all
C. the output at the present depends on the input at the current time
D. the output at the present depends on the input at a time instant in the future
4. The tree selected for the formation of state equations contains
A. all voltage sources
B. all capacitors
C. all inductors and current sources
D. all voltage sources and maximum number of capacitors
5. The Fourier series of an odd periodic function contains
A. odd harmonics only
B. even harmonics only
C. cosine harmonics only
D. sine harmonics only
6. With respect to time, ________is the rate of change
A. Amplitude
B. Time
C. Frequency
D. Voltage
7. Baseband transmission of a digital signal is possible only if we have a ____ channel.
A. low-pass
B. bandpass
C. low rate
D. high rate
8. The signal defined by the equations f(t) = 0 for t < 0, f(t) = E for 0 ? t ? a and f(t) = 0 for t > a is
A. a step function
B. a pulse function
C. a shifted step function originating at t = a
D. unit step function
9. For Ergodic Process
A. ensemble Average equal to time Average
B. ensemble Average is not equal to time Average
C. ensemble Average > Time Average
D. ensemble Average < Time Average
10. The inverse Laplace transform of 1/(s – a)2 is
A. eat
B. t eat
C. t2 eat
D. eat/t
11. Where does the maximum value of auto-correlation function of a power signal occur?
A. At origin
B. At extremities
C. At unity
D. At infinity
12. A signal g(t) = A then g(t) is a
A. energy signal
B. power signal
C. neither energy nor power signal
D. insufficient data
13. According to Rayleigh’s theorem, it becomes possible to determine the energy of a signal by________
A. Estimating the area under the square root of its amplitude spectrum
B. Estimating the area under the square of its amplitude spectrum
C. Estimating the area under the one-fourth power of its amplitude spectrum
D. Estimating the area exactly half as that of its amplitude spectrum
14. Where is the ROC defined or specified for the signals containing causal as well as anti-causal terms?
A. Greater than the largest pole
B. Less than the smallest pole
C. Between two poles
D. Cannot be defined
15. For a ______ channel, we need to use the Shannon capacity to find the maximum bit rate.
A. noisy
B. noiseless
C. bandpass
D. low-pass
16. The _____ of a composite signal is the difference between the highest and the lowest frequencies contained in that signal
A. frequency
B. period
C. bandwidth
D. amplitude
17. The integral of k u(t) is
A. 1/k ?(t)
B. k ?(t)
C. a ramp of slope 1/k
D. a ramp of slope k
18. Which among the following operations is/are not involved /associated with the computation process of linear convolution?
A. Folding Operation
B. Shifting Operation
C. Multiplication Operation
D. Integration Operation
19. Which type of system response to its input represents the zero value of its initial condition?
A. Zero state response
B. Zero input response
C. Total response
D. Natural response
20. For a second order system, damping ratio ? is such that 0 < ? <. Then the roots of characteristic equation are
A. real but not equal
B. imaginary
C. complex conjugate
D. real and equal
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