” ( 1 ) Unilateral Laplace Transform is applicable for the determination of

linear constant coefficient differential equations with ________

” 1) Zero

initial condition

” 2) Non-zero initial condition

” 3) Zero final

condition

” 4) Non-zero final condition

” 5) None of these

Answer :

2) Non-zero initial condition

Solution : Unilateral Laplace Transform is

applicable for the determination of linear constant coefficient differential

equations with Non-zero initial condition

” ( 2 ) Two rectangular waveforms

of duration t1 and t2 seconds are convolved. What is the shape of the resulting

waveform?

” 1) Triangular

” 2) Trapezoidal

” 3) Rectangular

” 4)

Semi-circular

” 5) circular

Answer : 2) Trapezoidal

Solution : If two

rectangular waveforms of duration t1 and t2 seconds are convolved. then the

shape of the resulting waveform is Trapezoidal.

” ( 3 ) What is the nature of

Fourier representation of a discrete & aperiodic signal?

” 1) Continuous

& periodic

” 2) Discrete and aperiodic

” 3) Continuous &

aperiodic

” 4) Discrete & periodic

” 5) None of these

Answer : 1)

Continuous & periodic

Solution : Fourier representation of a discrete

& aperiodic signal is Continuous & periodic.

” ( 4 ) Which property

of periodic signal in DTFS gets completely clarified / identified by the

equation x (n – n0 )?

” 1) Conjugation

” 2) Time Reversal

” 3)

Frequency Shifting

” 4) Time Shifting

” 5) None of these

Answer : 4)

Time Shifting

Solution : Time Shifting property of periodic signal in DTFS

gets completely clarified by the equation x (n – n0 ).

” ( 5) Duality Theorem

/ Property of Fourier Transform states that _________

” 1) Shape of signal in

time domain & shape of spectrum can be interchangeable

” 2) Shape of

signal in frequency domain & shape of spectrum can be interchangeable

”

3) Shape of signal in time domain & shape of spectrum can never be

interchangeable

” 4) Shape of signal in time domain & shape of spectrum

can never be interchangeable

” 5) None of these

Answer : 1) Shape of

signal in time domain & shape of spectrum can be interchangeable

Solution : Duality Theorem / Property of Fourier Transform states that Shape

of signal in time domain & shape of spectrum can be interchangeable.

”

( 6 ) 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 ?

” 1) Time Scaling

” 2)

Linearity

” 3) Time Shifting

” 4) Duality

” 5) None of

these

Answer : 3) Time Shifting

Solution : Time Shifting 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

” ( 7 ) Which among the following operations is/are not involved

/associated with the computation process of linear convolution?

” 1) Folding

Operation

” 2) Shifting Operation

” 3) Multiplication Operation

” 4)

Integration Operation

” 5) None of these

Answer : 4) Integration

Operation

Solution : Integration Operation is not associated with the

computation process of linear convolution.

” ( 8 ) Which type of system

response to its input represents the zero value of its initial condition?

”

1) Zero state response

” 2) Zero input response

” 3) Total response

” 4) Natural response

” 5) None of these

Answer : 1) Zero state

response

Solution : The zero state response (ZSR), also known as the forced

response is the behavior or response of a circuit with initial state of zero.

The ZSR results only from the external inputs or driving functions of the

circuit and not from the initial state. The ZSR is also called the forced or

driven response of the circuit.

” ( 9 ) Which among the following belongs to

the category of non-recursive systems?

” 1) Non-causal IIR Systems

” 2)

Causal IIR Systems

” 3) Non-causal FIR Systems

” 4) Causal FIR Systems

” 5) None of these

Answer : 4) Causal FIR Systems

Solution : Causal

FIR Systems is non-recursive systems.

” ( 10 ) Damped sinusoids are

_____

” 1) sinusoid signals multiplied by growing exponentials

” 2)

sinusoid signals divided by growing exponentials

” 3) sinusoid signals

multiplied by decaying exponentials

” 4) sinusoid signals divided by

decaying exponentials

” 5) None of these

Answer : 3) sinusoid signals

multiplied by decaying exponentials

Solution : Damped sinusoids are sinusoid

signals multiplied by decaying exponentials

” ( 11 ) Under which conditions

does an initially relaxed system become unstable ?

” 1) only if bounded input

generates unbounded output

” 2) only if bounded input generates bounded

output

” 3) only if unbounded input generates unbounded output

” 4) only

if unbounded input generates bounded output

” 5) None of these

Answer :

1) only if bounded input generates unbounded output

Solution : only if

bounded input generates unbounded output

” ( 12) All causal systems must have

the component of

” 1) memory

” 2) time invariance

” 3) stability

” 4) linearity

” 5) None of these

Answer : 1) memory

Solution :

All causal systems must have the component of memory

” ( 13 ) A system is

said to be defined as non causal, when

” 1) the output at the present depends

on the input at an earlier time

” 2) the output at the present does not

depend on the factor of time at all

” 3) the output at the present depends

on the input at the current time

” 4) the output at the present depends on

the input at a time instant in the future

” 5) None of these

Answer : 4)

the output at the present depends on the input at a time instant in the future

Solution : A non causal system’s output is said to depend on the input at a

time in the future.

” ( 314) A time invariant system is a system whose

output

” 1) vanishes with a delay in input

” 2) remains same with a delay

in input

” 3) decreases with a delay in input

” 4) increases with a

delay in input

Answer : 2) remains same with a delay in input

Solution :

A time invariant system’s output should be directly related to the time of the

output. There should be no scaling, i.e. y(t) = f(x(t)).

” ( 15) A system

which is linear is said to obey the rules of

” 1) homogeneity

” 2)

scaling

” 3) additivity

” 4) both scaling and additivity

” 5) None

of these

Answer : 4) both scaling and additivity

Solution : A system is

said to be additive and scalable in order to be classified as a linear

system.

” ( 16 ) Double integration of a unit step function would lead

to

” 1) an impulse

” 2) a parabola

” 3) a ramp

” 4) a doublet

” 5) None of these

Answer : 2) a parabola

Solution : Double

integration of a unit step function would lead to a parabola.

” ( 17 ) A

signal g(t) = A then g(t) is a

” 1) energy signal

” 2) power signal

”

3) neither energy nor power signal

” 4) insufficient data

” 5) both 1

& 2

Answer : 2) power signal

Solution : A signal g(t) = A then g(t)

is a power signal.

” ( 18 ) The Fourier series of an odd periodic function

contains

” 1) odd harmonics only

” 2) even harmonics only

” 3) cosine

harmonics only

” 4) sine harmonics only

” 5) None of these

Answer :

4) sine harmonics only

Solution : The Fourier series of an odd periodic

function contains sine harmonics only

” ( 19 ) As per time displacement

theorem in Laplace transformation, displacement in the time domain by T

becomes

” 1) division by s in the s domain

” 2) division by e-sT in the s

domain

” 3) multiplication by s in the s domain

” 4) multiplication by

e-sT in the s domain

” 5) None of these

Answer : 4) multiplication by

e-sT in the s domain

Solution : £f(t – T) = e-st F(s).

” ( 20 ) 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

” 1) a step function

” 2) a pulse function

” 3) a shifted step function originating at t = a

” 4) unit step

function

” 5) None of these

Answer : 2) a pulse function

Solution :

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 pulse function

” ( 21 ) Which one of the

following is correct? Energy of a power signal is

” 1) finite

” 2) zero

” 3) infinite

” 4) between 1 and 2

” 5) None of these

Answer : 3)

infinite

Solution : Energy of a power signal is infinite

” ( 22 ) Auto

correlation function

” 1) is an even function of t

” 2) is an odd

function of t

” 3) may be an even or odd function of t

” 4) is both an

odd and even function of t

” 5) None of these

Answer : 1) is an even

function of t

Solution : Auto correlation function is an even function of

t

” ( 23 ) In RLC circuits the state variables generally selected are

” 1)

voltages across capacitors

” 2) currents through resistances and voltages

across capacitors

” 3) currents through resistances and capacitances

”

4) currents through inductances and voltages across capacitances

” 5) None

of these

Answer : 4) currents through inductances and voltages across

capacitances

Solution : In RLC circuits the state variables generally

selected are currents through inductances and voltages across capacitances.

”

( 24 ) The theoretical power of white noise is

” 1) infninite

” 2) depend

upon frequency of signal

” 3) finite

” 4) zero

” 5) None of

these

Answer : 2) depend upon frequency of signal

Solution : The

theoretical power of white noise is depend upon frequency of signal

” ( 25 )

If f(t) is an even function, the coefficients Fn in the exponential form of

Fourier series

” 1) are real

” 2) are imaginary

” 3) are complex

” 4) may be real or imaginary

” 5) None of these

Answer : 1) are real

Solution : If f(t) is an even function, the coefficients Fn in the

exponential form of Fourier series are real

” ( 26 ) For a ______ channel, we

need to use the Shannon capacity to find the maximum bit rate.

” 1) noisy

” 2) noiseless

” 3) bandpass

” 4) low-pass

” 5) low

rate

Answer : 1) noisy

Solution : For a noisy channel, we need to use the

Shannon capacity to find the maximum bit rate.

” ( 27 ) For a ______ channel,

the Nyquist bit rate formula defines the theoretical maximum bit rate.

” 1)

noisy

” 2) noiseless

” 3) bandpass

” 4) low-pass

” 5) low

rate

Answer : 2) noiseless

Solution : For a noiseless channel, the

Nyquist bit rate formula defines the theoretical maximum bit rate.

” ( 28 )

Baseband transmission of a digital signal is possible only if we have a ____

channel.

” 1) low-pass

” 2) bandpass

” 3) low rate

” 4) high rate

” 5) None of these

Answer : 1) low-pass

Solution : Baseband

transmission of a digital signal is possible only if we have a low-pass

channel.

” ( 29 ) The _____ of a composite signal is the difference between

the highest and the lowest frequencies contained in that signal

” 1)

frequency

” 2) period

” 3) bandwidth

” 4) amplitude

” 5) None of

these

Answer : 3) bandwidth

Solution : The bandwidth of a composite

signal is the difference between the highest and the lowest frequencies

contained in that signal

” ( 30 ) A sine wave in the ______ domain can be

represented by one single spike in the _____ domain.

” 1) time; frequency

” 2) frequency; time

” 3) time; phase

” 4) phase; time

” 5) None

of these

Answer : 1) time; frequency

Solution : A sine wave in the time

domain can be represented by one single spike in the frequency domain.

” ( 31

) ________is the rate of change with respect to time.

” 1) Amplitude

” 2)

Time

” 3) Frequency

” 4) Voltage

” 5) None of these

Answer : 3)

Frequency

Solution : Frequency is the rate of change with respect to

time.

” ( 32 ) What does the spectral density function of any signal

specify?

” 1) Distribution of energy or power

” 2) Consumption of energy

or power

” 3) Conservation of energy or power

” 4) Generation of energy

or power

” 5) None of these

Answer : 1) Distribution of energy or power

Solution : the spectral density function of any signal specify distribution

of energy or power

” ( 33 ) The ESD of a real valued energy signal is always

________

” 1) An even (symmetric) function of frequency

” 2) An odd

(non-symmetric) function of frequency

” 3) A function that is odd and

half-wave symmetric

” 4) None of the above

Answer : 1) An even

(symmetric) function of frequency

Solution : The ESD of a real valued energy

signal is always n even (symmetric) function of frequency

” ( 34 ) Where does

the maximum value of auto-correlation function of a power signal occur?

” 1)

At origin

” 2) At extremities

” 3) At unity

” 4) At infinity

”

5) None of these

Answer : 1) At origin

Solution : At origin the maximum

value of auto-correlation function of a power signal occur.

” ( 35 ) What

would happen if the value of term [(m-x) / (? ? 2)] increases in the expression

of Guassian CDF?

” 1) Complementary error function also goes on increasing

” 2) Complementary error function goes on decreasing

” 3) Complementary

error function remains constant or unchanged

” 4) Cannot predict

” 5)

None of these

Answer : 2) Complementary error function goes on decreasing

Solution : if the value of term [(m-x) / (? ? 2)] increases in the

expression of Guassian CDF Complementary error function goes on decreasing

”

( 36 ) What is the value of an area under the conditional PDF ?

” 1) Greater

than ‘0’ but less than ‘1’

” 2) Greater than ‘1’

” 3) Equal to ‘1’

”

4) Infinite

” 5) None of these

Answer : 3) Equal to ‘1’

Solution :

the value of an area under the conditional PDF equal to 1

” ( 37 ) According

to Rayleigh’s theorem, it becomes possible to determine the energy of a signal

by________

” 1) Estimating the area under the square root of its amplitude

spectrum

” 2) Estimating the area under the square of its amplitude spectrum

” 3) Estimating the area under the one-fourth power of its amplitude

spectrum

” 4) Estimating the area exactly half as that of its amplitude

spectrum

” 5) None of these

Answer : 2) Estimating the area under the

square of its amplitude spectrum

Solution : According to Rayleigh’s theorem,

it becomes possible to determine the energy of a signal by Estimating the area

under the square of its amplitude spectrum.

” ( 38 ) Where is the ROC defined

or specified for the signals containing causal as well as anti-causal

terms?

” 1) Greater than the largest pole

” 2) Less than the smallest

pole

” 3) Between two poles

” 4) Cannot be defined

Answer : 3)

Between two poles

Solution : ROC defined Between two poles for the signals

containing causal as well as anti-causal terms.

” ( 39 ) According to the

time-shifting property of Laplace Transform, shifting the signal in time domain

corresponds to the ______

” 1) Multiplication by e-st0 in the time domain

” 2) Multiplication by e-st0 in the frequency domain

” 3) Multiplication

by est0 in the time domain

” 4) Multiplication by est0 in the frequency

domain

” 5) None of these

Answer : 2) Multiplication by e-st0 in the

frequency domain

Solution : According to the time-shifting property of

Laplace Transform, shifting the signal in time domain corresponds to the

Multiplication by e-st0 in the frequency domain

” ( 40 ) Which result is

generated/ obtained by the addition of a step to a ramp function ?

” 1) Step

function of zero slope

” 2) Ramp function of zero slope

” 3) Ramp

Function shifted by an amount equal to step

” 4) Step Function shifted by an

amount equal to ramp

” 5) None of these

Answer : 3) Ramp Function shifted

by an amount equal to step

Solution : Ramp Function shifted by an amount

equal to step by the addition of a step to a ramp function.

” ( 41 )

Generally, the convolution process associated with the Laplace Transform in time

domain results into________

” 1) Simple multiplication in complex frequency

domain

” 2) Simple division in complex frequency domain

” 3) Simple

multiplication in complex time domain

” 4) Simple division in complex time

domain

” 5) None of these

” ( 42 ) The tree selected for the formation of

state equations contains

” 1) all voltage sources

” 2) all capacitors

” 3) all inductors and current sources

” 4) all voltage sources and

maximum number of capacitors

” 5) None of these

Answer : 4) all voltage

sources and maximum number of capacitors

Solution : The tree selected for

the formation of state equations contains all voltage sources and maximum number

of capacitors

” ( 43 ) For a second order system, damping ratio ? is such

that 0 < ? <. Then the roots of characteristic equation are

” 1) real

but not equal

” 2) imaginary

” 3) complex conjugate

” 4) real and

equal

” 5) None of these

Answer : 3) complex conjugate

Solution : For

a second order system, damping ratio ? is such that 0 < ? <. Then the

roots of characteristic equation are complex conjugate

” ( 44 ) The inverse

Laplace transform of 1/(s – a)2 is

” 1) eat

” 2) t eat

” 3) t2 eat

” 4) eat/t

” 5) t/eat

Answer : 2) t eat

Solution : The inverse

Laplace transform of 1/(s – a)2 is t eat

” ( 45 ) The discrete time system

describes by y(n) = x(n2) is

” 1) non-casual, non-linear, time variant

”

2) non-casual, Linear, time invariant

” 3) casual, non-linear, timevari

” 4) casual, Linear, time varying

” 5) casual, Linear, time

invariant

Answer : 4) casual, Linear, time varying

Solution : The

discrete time system describes by y(n) = x(n2) is casual, Linear and time

varying

” ( 46 ) The integral of k u(t) is

” 1) 1/k ?(t)

” 2) k ?(t)

” 3) a ramp of slope 1/k

” 4) a ramp of slope k

” 5) None of

these

Answer : 4) a ramp of slope k

Solution : The integral of k u(t) is

a ramp of slope k

” ( 47 ) In a complex wave, the negative half of the wave

is a reproduction of the positive half wave. Then

” 1) the wave does not

contain triple harmonics

” 2) the wave does not contain odd harmonics

”

3) the wave does not contain even harmonics

” 4) the wave contains only

fundamental and third harmonic

Answer : 3) the wave does not contain even

harmonics

Solution : In a complex wave, the negative half of the wave is a

reproduction of the positive half wave. Then the wave does not contain even

harmonics

” ( 48 ) Which of the following is/are not a property/properties

power spectral density function Sx(?)?

” 1) Sx(?) is real function of ?

”

2) Sx(?) is a even function of ?

” 3) Sx(?) is a odd function of ?

” 4)

Sx(?) is non-positive function of ?Sx(?) ? 0 for all ?

” 5) All of the

above

Answer : 4) Sx(?) is non-positive function of ?Sx(?) ? 0 for all ?

Solution : Properties of power spectral density function Sx(?):

Sx(?) is

real function of ?

Sx(?) is a even function of ?

Sx(?) is a odd function

of ?

” ( 49 ) For Ergodic Process

” 1) ensemble Average equal to time

Average

” 2) ensemble Average is not equal to time Average

” 3) ensemble

Average > Time Average

” 4) ensemble Average < Time Average

” 5)

both 1 & 3

Answer : 1) ensemble Average equal to time Average

Solution : For Ergodic Process ensemble Average equal to time Average

”

( 50 ) FIR digital filter having __________ stability than FIR filter.

” 1)

good stability

” 2) poor stability

” 3) stability not guarnteed

” 4)

poor stability

” 5) None of these

Answer : 1) good stability

Solution

: FIR digital filter having good stability stability than FIR filter.

linear constant coefficient differential equations with ________

” 1) Zero

initial condition

” 2) Non-zero initial condition

” 3) Zero final

condition

” 4) Non-zero final condition

” 5) None of these

Answer :

2) Non-zero initial condition

Solution : Unilateral Laplace Transform is

applicable for the determination of linear constant coefficient differential

equations with Non-zero initial condition

” ( 2 ) Two rectangular waveforms

of duration t1 and t2 seconds are convolved. What is the shape of the resulting

waveform?

” 1) Triangular

” 2) Trapezoidal

” 3) Rectangular

” 4)

Semi-circular

” 5) circular

Answer : 2) Trapezoidal

Solution : If two

rectangular waveforms of duration t1 and t2 seconds are convolved. then the

shape of the resulting waveform is Trapezoidal.

” ( 3 ) What is the nature of

Fourier representation of a discrete & aperiodic signal?

” 1) Continuous

& periodic

” 2) Discrete and aperiodic

” 3) Continuous &

aperiodic

” 4) Discrete & periodic

” 5) None of these

Answer : 1)

Continuous & periodic

Solution : Fourier representation of a discrete

& aperiodic signal is Continuous & periodic.

” ( 4 ) Which property

of periodic signal in DTFS gets completely clarified / identified by the

equation x (n – n0 )?

” 1) Conjugation

” 2) Time Reversal

” 3)

Frequency Shifting

” 4) Time Shifting

” 5) None of these

Answer : 4)

Time Shifting

Solution : Time Shifting property of periodic signal in DTFS

gets completely clarified by the equation x (n – n0 ).

” ( 5) Duality Theorem

/ Property of Fourier Transform states that _________

” 1) Shape of signal in

time domain & shape of spectrum can be interchangeable

” 2) Shape of

signal in frequency domain & shape of spectrum can be interchangeable

”

3) Shape of signal in time domain & shape of spectrum can never be

interchangeable

” 4) Shape of signal in time domain & shape of spectrum

can never be interchangeable

” 5) None of these

Answer : 1) Shape of

signal in time domain & shape of spectrum can be interchangeable

Solution : Duality Theorem / Property of Fourier Transform states that Shape

of signal in time domain & shape of spectrum can be interchangeable.

”

( 6 ) 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 ?

” 1) Time Scaling

” 2)

Linearity

” 3) Time Shifting

” 4) Duality

” 5) None of

these

Answer : 3) Time Shifting

Solution : Time Shifting 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

” ( 7 ) Which among the following operations is/are not involved

/associated with the computation process of linear convolution?

” 1) Folding

Operation

” 2) Shifting Operation

” 3) Multiplication Operation

” 4)

Integration Operation

” 5) None of these

Answer : 4) Integration

Operation

Solution : Integration Operation is not associated with the

computation process of linear convolution.

” ( 8 ) Which type of system

response to its input represents the zero value of its initial condition?

”

1) Zero state response

” 2) Zero input response

” 3) Total response

” 4) Natural response

” 5) None of these

Answer : 1) Zero state

response

Solution : The zero state response (ZSR), also known as the forced

response is the behavior or response of a circuit with initial state of zero.

The ZSR results only from the external inputs or driving functions of the

circuit and not from the initial state. The ZSR is also called the forced or

driven response of the circuit.

” ( 9 ) Which among the following belongs to

the category of non-recursive systems?

” 1) Non-causal IIR Systems

” 2)

Causal IIR Systems

” 3) Non-causal FIR Systems

” 4) Causal FIR Systems

” 5) None of these

Answer : 4) Causal FIR Systems

Solution : Causal

FIR Systems is non-recursive systems.

” ( 10 ) Damped sinusoids are

_____

” 1) sinusoid signals multiplied by growing exponentials

” 2)

sinusoid signals divided by growing exponentials

” 3) sinusoid signals

multiplied by decaying exponentials

” 4) sinusoid signals divided by

decaying exponentials

” 5) None of these

Answer : 3) sinusoid signals

multiplied by decaying exponentials

Solution : Damped sinusoids are sinusoid

signals multiplied by decaying exponentials

” ( 11 ) Under which conditions

does an initially relaxed system become unstable ?

” 1) only if bounded input

generates unbounded output

” 2) only if bounded input generates bounded

output

” 3) only if unbounded input generates unbounded output

” 4) only

if unbounded input generates bounded output

” 5) None of these

Answer :

1) only if bounded input generates unbounded output

Solution : only if

bounded input generates unbounded output

” ( 12) All causal systems must have

the component of

” 1) memory

” 2) time invariance

” 3) stability

” 4) linearity

” 5) None of these

Answer : 1) memory

Solution :

All causal systems must have the component of memory

” ( 13 ) A system is

said to be defined as non causal, when

” 1) the output at the present depends

on the input at an earlier time

” 2) the output at the present does not

depend on the factor of time at all

” 3) the output at the present depends

on the input at the current time

” 4) the output at the present depends on

the input at a time instant in the future

” 5) None of these

Answer : 4)

the output at the present depends on the input at a time instant in the future

Solution : A non causal system’s output is said to depend on the input at a

time in the future.

” ( 314) A time invariant system is a system whose

output

” 1) vanishes with a delay in input

” 2) remains same with a delay

in input

” 3) decreases with a delay in input

” 4) increases with a

delay in input

Answer : 2) remains same with a delay in input

Solution :

A time invariant system’s output should be directly related to the time of the

output. There should be no scaling, i.e. y(t) = f(x(t)).

” ( 15) A system

which is linear is said to obey the rules of

” 1) homogeneity

” 2)

scaling

” 3) additivity

” 4) both scaling and additivity

” 5) None

of these

Answer : 4) both scaling and additivity

Solution : A system is

said to be additive and scalable in order to be classified as a linear

system.

” ( 16 ) Double integration of a unit step function would lead

to

” 1) an impulse

” 2) a parabola

” 3) a ramp

” 4) a doublet

” 5) None of these

Answer : 2) a parabola

Solution : Double

integration of a unit step function would lead to a parabola.

” ( 17 ) A

signal g(t) = A then g(t) is a

” 1) energy signal

” 2) power signal

”

3) neither energy nor power signal

” 4) insufficient data

” 5) both 1

& 2

Answer : 2) power signal

Solution : A signal g(t) = A then g(t)

is a power signal.

” ( 18 ) The Fourier series of an odd periodic function

contains

” 1) odd harmonics only

” 2) even harmonics only

” 3) cosine

harmonics only

” 4) sine harmonics only

” 5) None of these

Answer :

4) sine harmonics only

Solution : The Fourier series of an odd periodic

function contains sine harmonics only

” ( 19 ) As per time displacement

theorem in Laplace transformation, displacement in the time domain by T

becomes

” 1) division by s in the s domain

” 2) division by e-sT in the s

domain

” 3) multiplication by s in the s domain

” 4) multiplication by

e-sT in the s domain

” 5) None of these

Answer : 4) multiplication by

e-sT in the s domain

Solution : £f(t – T) = e-st F(s).

” ( 20 ) 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

” 1) a step function

” 2) a pulse function

” 3) a shifted step function originating at t = a

” 4) unit step

function

” 5) None of these

Answer : 2) a pulse function

Solution :

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 pulse function

” ( 21 ) Which one of the

following is correct? Energy of a power signal is

” 1) finite

” 2) zero

” 3) infinite

” 4) between 1 and 2

” 5) None of these

Answer : 3)

infinite

Solution : Energy of a power signal is infinite

” ( 22 ) Auto

correlation function

” 1) is an even function of t

” 2) is an odd

function of t

” 3) may be an even or odd function of t

” 4) is both an

odd and even function of t

” 5) None of these

Answer : 1) is an even

function of t

Solution : Auto correlation function is an even function of

t

” ( 23 ) In RLC circuits the state variables generally selected are

” 1)

voltages across capacitors

” 2) currents through resistances and voltages

across capacitors

” 3) currents through resistances and capacitances

”

4) currents through inductances and voltages across capacitances

” 5) None

of these

Answer : 4) currents through inductances and voltages across

capacitances

Solution : In RLC circuits the state variables generally

selected are currents through inductances and voltages across capacitances.

”

( 24 ) The theoretical power of white noise is

” 1) infninite

” 2) depend

upon frequency of signal

” 3) finite

” 4) zero

” 5) None of

these

Answer : 2) depend upon frequency of signal

Solution : The

theoretical power of white noise is depend upon frequency of signal

” ( 25 )

If f(t) is an even function, the coefficients Fn in the exponential form of

Fourier series

” 1) are real

” 2) are imaginary

” 3) are complex

” 4) may be real or imaginary

” 5) None of these

Answer : 1) are real

Solution : If f(t) is an even function, the coefficients Fn in the

exponential form of Fourier series are real

” ( 26 ) For a ______ channel, we

need to use the Shannon capacity to find the maximum bit rate.

” 1) noisy

” 2) noiseless

” 3) bandpass

” 4) low-pass

” 5) low

rate

Answer : 1) noisy

Solution : For a noisy channel, we need to use the

Shannon capacity to find the maximum bit rate.

” ( 27 ) For a ______ channel,

the Nyquist bit rate formula defines the theoretical maximum bit rate.

” 1)

noisy

” 2) noiseless

” 3) bandpass

” 4) low-pass

” 5) low

rate

Answer : 2) noiseless

Solution : For a noiseless channel, the

Nyquist bit rate formula defines the theoretical maximum bit rate.

” ( 28 )

Baseband transmission of a digital signal is possible only if we have a ____

channel.

” 1) low-pass

” 2) bandpass

” 3) low rate

” 4) high rate

” 5) None of these

Answer : 1) low-pass

Solution : Baseband

transmission of a digital signal is possible only if we have a low-pass

channel.

” ( 29 ) The _____ of a composite signal is the difference between

the highest and the lowest frequencies contained in that signal

” 1)

frequency

” 2) period

” 3) bandwidth

” 4) amplitude

” 5) None of

these

Answer : 3) bandwidth

Solution : The bandwidth of a composite

signal is the difference between the highest and the lowest frequencies

contained in that signal

” ( 30 ) A sine wave in the ______ domain can be

represented by one single spike in the _____ domain.

” 1) time; frequency

” 2) frequency; time

” 3) time; phase

” 4) phase; time

” 5) None

of these

Answer : 1) time; frequency

Solution : A sine wave in the time

domain can be represented by one single spike in the frequency domain.

” ( 31

) ________is the rate of change with respect to time.

” 1) Amplitude

” 2)

Time

” 3) Frequency

” 4) Voltage

” 5) None of these

Answer : 3)

Frequency

Solution : Frequency is the rate of change with respect to

time.

” ( 32 ) What does the spectral density function of any signal

specify?

” 1) Distribution of energy or power

” 2) Consumption of energy

or power

” 3) Conservation of energy or power

” 4) Generation of energy

or power

” 5) None of these

Answer : 1) Distribution of energy or power

Solution : the spectral density function of any signal specify distribution

of energy or power

” ( 33 ) The ESD of a real valued energy signal is always

________

” 1) An even (symmetric) function of frequency

” 2) An odd

(non-symmetric) function of frequency

” 3) A function that is odd and

half-wave symmetric

” 4) None of the above

Answer : 1) An even

(symmetric) function of frequency

Solution : The ESD of a real valued energy

signal is always n even (symmetric) function of frequency

” ( 34 ) Where does

the maximum value of auto-correlation function of a power signal occur?

” 1)

At origin

” 2) At extremities

” 3) At unity

” 4) At infinity

”

5) None of these

Answer : 1) At origin

Solution : At origin the maximum

value of auto-correlation function of a power signal occur.

” ( 35 ) What

would happen if the value of term [(m-x) / (? ? 2)] increases in the expression

of Guassian CDF?

” 1) Complementary error function also goes on increasing

” 2) Complementary error function goes on decreasing

” 3) Complementary

error function remains constant or unchanged

” 4) Cannot predict

” 5)

None of these

Answer : 2) Complementary error function goes on decreasing

Solution : if the value of term [(m-x) / (? ? 2)] increases in the

expression of Guassian CDF Complementary error function goes on decreasing

”

( 36 ) What is the value of an area under the conditional PDF ?

” 1) Greater

than ‘0’ but less than ‘1’

” 2) Greater than ‘1’

” 3) Equal to ‘1’

”

4) Infinite

” 5) None of these

Answer : 3) Equal to ‘1’

Solution :

the value of an area under the conditional PDF equal to 1

” ( 37 ) According

to Rayleigh’s theorem, it becomes possible to determine the energy of a signal

by________

” 1) Estimating the area under the square root of its amplitude

spectrum

” 2) Estimating the area under the square of its amplitude spectrum

” 3) Estimating the area under the one-fourth power of its amplitude

spectrum

” 4) Estimating the area exactly half as that of its amplitude

spectrum

” 5) None of these

Answer : 2) Estimating the area under the

square of its amplitude spectrum

Solution : According to Rayleigh’s theorem,

it becomes possible to determine the energy of a signal by Estimating the area

under the square of its amplitude spectrum.

” ( 38 ) Where is the ROC defined

or specified for the signals containing causal as well as anti-causal

terms?

” 1) Greater than the largest pole

” 2) Less than the smallest

pole

” 3) Between two poles

” 4) Cannot be defined

Answer : 3)

Between two poles

Solution : ROC defined Between two poles for the signals

containing causal as well as anti-causal terms.

” ( 39 ) According to the

time-shifting property of Laplace Transform, shifting the signal in time domain

corresponds to the ______

” 1) Multiplication by e-st0 in the time domain

” 2) Multiplication by e-st0 in the frequency domain

” 3) Multiplication

by est0 in the time domain

” 4) Multiplication by est0 in the frequency

domain

” 5) None of these

Answer : 2) Multiplication by e-st0 in the

frequency domain

Solution : According to the time-shifting property of

Laplace Transform, shifting the signal in time domain corresponds to the

Multiplication by e-st0 in the frequency domain

” ( 40 ) Which result is

generated/ obtained by the addition of a step to a ramp function ?

” 1) Step

function of zero slope

” 2) Ramp function of zero slope

” 3) Ramp

Function shifted by an amount equal to step

” 4) Step Function shifted by an

amount equal to ramp

” 5) None of these

Answer : 3) Ramp Function shifted

by an amount equal to step

Solution : Ramp Function shifted by an amount

equal to step by the addition of a step to a ramp function.

” ( 41 )

Generally, the convolution process associated with the Laplace Transform in time

domain results into________

” 1) Simple multiplication in complex frequency

domain

” 2) Simple division in complex frequency domain

” 3) Simple

multiplication in complex time domain

” 4) Simple division in complex time

domain

” 5) None of these

” ( 42 ) The tree selected for the formation of

state equations contains

” 1) all voltage sources

” 2) all capacitors

” 3) all inductors and current sources

” 4) all voltage sources and

maximum number of capacitors

” 5) None of these

Answer : 4) all voltage

sources and maximum number of capacitors

Solution : The tree selected for

the formation of state equations contains all voltage sources and maximum number

of capacitors

” ( 43 ) For a second order system, damping ratio ? is such

that 0 < ? <. Then the roots of characteristic equation are

” 1) real

but not equal

” 2) imaginary

” 3) complex conjugate

” 4) real and

equal

” 5) None of these

Answer : 3) complex conjugate

Solution : For

a second order system, damping ratio ? is such that 0 < ? <. Then the

roots of characteristic equation are complex conjugate

” ( 44 ) The inverse

Laplace transform of 1/(s – a)2 is

” 1) eat

” 2) t eat

” 3) t2 eat

” 4) eat/t

” 5) t/eat

Answer : 2) t eat

Solution : The inverse

Laplace transform of 1/(s – a)2 is t eat

” ( 45 ) The discrete time system

describes by y(n) = x(n2) is

” 1) non-casual, non-linear, time variant

”

2) non-casual, Linear, time invariant

” 3) casual, non-linear, timevari

” 4) casual, Linear, time varying

” 5) casual, Linear, time

invariant

Answer : 4) casual, Linear, time varying

Solution : The

discrete time system describes by y(n) = x(n2) is casual, Linear and time

varying

” ( 46 ) The integral of k u(t) is

” 1) 1/k ?(t)

” 2) k ?(t)

” 3) a ramp of slope 1/k

” 4) a ramp of slope k

” 5) None of

these

Answer : 4) a ramp of slope k

Solution : The integral of k u(t) is

a ramp of slope k

” ( 47 ) In a complex wave, the negative half of the wave

is a reproduction of the positive half wave. Then

” 1) the wave does not

contain triple harmonics

” 2) the wave does not contain odd harmonics

”

3) the wave does not contain even harmonics

” 4) the wave contains only

fundamental and third harmonic

Answer : 3) the wave does not contain even

harmonics

Solution : In a complex wave, the negative half of the wave is a

reproduction of the positive half wave. Then the wave does not contain even

harmonics

” ( 48 ) Which of the following is/are not a property/properties

power spectral density function Sx(?)?

” 1) Sx(?) is real function of ?

”

2) Sx(?) is a even function of ?

” 3) Sx(?) is a odd function of ?

” 4)

Sx(?) is non-positive function of ?Sx(?) ? 0 for all ?

” 5) All of the

above

Answer : 4) Sx(?) is non-positive function of ?Sx(?) ? 0 for all ?

Solution : Properties of power spectral density function Sx(?):

Sx(?) is

real function of ?

Sx(?) is a even function of ?

Sx(?) is a odd function

of ?

” ( 49 ) For Ergodic Process

” 1) ensemble Average equal to time

Average

” 2) ensemble Average is not equal to time Average

” 3) ensemble

Average > Time Average

” 4) ensemble Average < Time Average

” 5)

both 1 & 3

Answer : 1) ensemble Average equal to time Average

Solution : For Ergodic Process ensemble Average equal to time Average

”

( 50 ) FIR digital filter having __________ stability than FIR filter.

” 1)

good stability

” 2) poor stability

” 3) stability not guarnteed

” 4)

poor stability

” 5) None of these

Answer : 1) good stability

Solution

: FIR digital filter having good stability stability than FIR filter.

Thank you sir for electronics material .