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. 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
3. 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
4. Duality Theorem / Property of Fourier Transform states that _________
A. Shape of signal in time domain & shape of spectrum can be interchangeable
B. Shape of signal in frequency domain & shape of spectrum can be interchangeable
C. Shape of signal in time domain & shape of spectrum can never be interchangeable
D. Shape of signal in time domain & shape of spectrum can never be interchangeable
5. 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
6. The theoretical power of white noise is
A. infninite
B. depend upon frequency of signal
C. finite
D. zero
7. Auto correlation function
A. is an even function of t
B. is an odd function of t
C. may be an even or odd function of t
D. is both an odd and even function of t
8. 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
9. Generally, the convolution process associated with the Laplace Transform in time domain results into________
A. Simple multiplication in complex frequency domain
B. Simple division in complex frequency domain
C. Simple multiplication in complex time domain
D. Simple division in complex time domain
10. Unilateral Laplace Transform is applicable for the determination of linear constant coefficient differential equations with ________
A. Zero initial condition
B. Non-zero initial condition
C. Zero final condition
D. Non-zero final condition
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. Which property of periodic signal in DTFS gets completely clarified / identified by the equation x (n – n0 )?
A. Conjugation
B. Time Reversal
C. Frequency Shifting
D. Time Shifting
13. A system which is linear is said to obey the rules of
A. homogeneity
B. scaling
C. additivity
D. both scaling and additivity
14. Which property of fourier transform gives rise to an additional phase shift of -2? ftd for the generated time delay in the communication system without affecting an amplitude spectrum ?
A. Time Scaling
B. Linearity
C. Time Shifting
D. Duality
15. 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
16. 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
17. With respect to time, ________is the rate of change
A. Amplitude
B. Time
C. Frequency
D. Voltage
18. For a ______ channel,the Nyquist bit rate formula defines the theoretical maximum bit rate.
A. noisy
B. noiseless
C. bandpass
D. low-pass rate
19. In RLC circuits the state variables generally selected are
A. voltages across capacitors
B. currents through resistances and voltages across capacitors
C. currents through resistances and capacitances
D. currents through inductances and voltages across capacitances
20. Damped sinusoids are _____
A. sinusoid signals multiplied by growing exponentials
B. sinusoid signals divided by growing exponentials
C. sinusoid signals multiplied by decaying exponentials
D. sinusoid signals divided by decaying exponentials
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