Que. 1 For a secound order system with the close loop transfer function
T(s)= 9/[s^2+4s+9] the setting time for 2% band in secounds
is
A 1.5
B 2.0
C 3.0
D 4.0
Que. 2 The Nyquist sampling interval,for the signal sinc(700t)+sinc(500t) is
A 1/350 sec
B (pi)/350 sec
C 1/700 sec
D (pi)/175 sec
Que. 3 A video transmission system transmitts 625 picture frames/sec. Each frame
consist of a (400*400) pixel grid with 64 intensity levals/pixal.The
data rate of the system is
A 16Mbps
B 100Mbps
C 600Mbps
D 6.4Mbps
Que. 4 Let x and y be two statistically independent random variables uniformly
distributed in the ranges (-1,1)and(-2,1) respectively let Z=x+y, then
the probality that is
A 0
B 1/6
C 1/3
D 1/12
Que. 5 The gain margin and the phase margin of a feedback system with G(s)H(s)=s/(s+100)^3
are
A 0db,0degree
B infinite,infinite
C infinite,0degree
D 88.5dB,infinite
Que. 6 For the polynomial P(s)=s^5+s^4+2s^3+2s^2+3s+15,the number of root which
is right halfe of the s-plane is
A 4
B 2
C 3
D 1
Que. 7 Laplace transform of tsin at is
A 2as/[(s^2)+(a^2)]^2
B 2a/[(s^2+a^2)]^2
C 2s/[(s^2)+(a^2)]^2
D a/[(s^2+a^2)]^2
Que. 8 1Khz sinusoidal signal is ideally sampled at 1500 samples/sec and the
sasmpled signal is passed though an ideal low-pass filter with cutoff
freq. 800hz the output signal has freq.
A 0 hz
B 0.75Khz
C 0.5Khz
D 0.25Khz
Que. 9 A system function has a pole at s=0 and a zero at s=-1 the constant multiplier
is unity for an exitation cos t, the steady state response is given by
A [(sqrt)2] cos(t+45degree)
B [(sqrt)2] cos(t-45degree)
C cos45degree
D 1/[(sqrt)2] cos(t+45degree)
Que. 10 For a liner transfer function of the variable, the transfer function of
the system
A changes
B does not change
C has no relation at all
D depends on other fectors also
Que. 11 Asignal phase voltage source square wave inverter feeds pure inductive
load.The waveform of the load current will be
A sinusodal
B rectangular
C trapezoidal
D triangular
Que. 12 The unit ckt of the Nyquist plot transforms into 0dB line of the amplitude
plot the bode digram at
A 0 frequency
B low frequency
C high frequency
D any frequency
Que. 13 An instruction used to set the carry flag in a computer can be classified
as
A data transfer
B arithmetic
C logical
D program control
Que. 14 a system function H(s)=V(s)/I(s)=s+2/2s+1 the system is at rest
for t<0.i(t)=unit step. the value of v(t) at t=0 and t=infinite respectively
are
A 2 and 1/2
B 1/2 and 2
C 0 and indetermined
D 2 and indetermined
Que. 15 H(s)=V(s)/I(s)=4s+6/s+2, i(t)=unit step function. v(t) as t->infinite
is given by
A 0
B 3
C 4
D infinite
Que. 16 A driving point impedance Z(s)=V(s)/I(s)=s+1/s+2. the system is initally
at rest for a voltage a signal at unit step, the current i(t) through
Z is given by
A 1-e^-r
B 2-e^-r
C 2-2e^-r
D 1/2e^-r
Que. 17 For the random variable x following the probality density function p(x) shows in fig. the mean and the variance are respectively
^
| P(x)
|
1/4 _____|___________
| | | |
| | |
___|____|___________|_______ x
-1 0 3 ---->
A 1/2 and 2/3
B 1 and 4/3
C 1 and 2/3
D 2 and 4/3
Que. 18 If R is the source resistance the output resistance of an emittor follower
using the s simplified hybrid model would be
A h(ie)+R(s) /1+h(fe)
B h(ie) +R(s) /h(fe)
C R(s) +1/h(fe)
D 1/h(fe)
Que. 19 A unit feedback system has an open-loop transfer function of
G(s)=1000/s(s+10)^2 the magnitude of G(jw) in
the DB at an angular frequency at w= 20 red/sec
A 0dB
B 10dB
C 20dB
D none of the above
Que. 20 A linear discreate time system has the characteristic equation Z^3-0.81Z=0.the
system
A is stable
B is marginally stable
C is unstable
D stability can not be assessed from the given information
Que. 21 H(s)=V(s)/I(s) = s+3/(s+3)^2 .i(t) is unit step.V(t)
is steady state is given by
A 3/2
B 3/4
C 1
D 0
Que. 22 In case of synchro error dector,the electrical zreo position of control
transformer is obtained when angular displacement between rotors is
A 0
B 45degree
C 90degree
D 180degree
Que. 23 A second order differential equation is given by
d^2x/dt^2+5dx/dt+7x=7y The undamped natural freq. and damping ratio are
A 1,5
B 5,7
C 1,[(sqrt)7]
D [(sqrt)7],0.94
Que. 24 An amplifier has a bandwidth of 20khz and a midband gain of 50 without
feedback.If a -ve feedback of 1% is applied.then bandwidth with feedback
is
A 13.3khz
B 30khz
C 10khz
D 40khz
Que. 25 A unity feedback system has the plan transfer function Gp
(s)=1/[(s+1)(2s+1) ] an integral controller with transfer function G
(s)=k/s is placed in the feedforward path the of the feedback system.
the value of k such that the compensated system has an open loop gain
margin of 2.5
A 3/5
B 5/3
C 2
D none of the above
Que. 26 The fourier transform of the unit step function is
A f(jw)=j/w
B f(jw)=jw
C f(jw)=1/jw
D f(jw)=1/w
Que. 27 The fourier transform of function f(at) is given by
A f(at)=aF(w)
B f(at)=2/a F(w)
C f(at)=1/a F(w/a)
D none
Que. 28 The eigen value of the matrix A= |0 1| are
|1 0|
A 1,1
B -1,-1
C j,-j
D 1,-1
Que. 29 the trigonometric fourier series ofa perodic function can have only
A cosine term
B sine term
C cosine and sine term
D none of these
Que. 30 inverse Laplace transform of 10/(s^2)+2s+5 is
A 10 (e^-t) sin2t
B 5 (e^-t) sin2t
C 10 (e^-t) cos2t
D 5 (e^-t) cos2t
Que. 31 Laplace transform of (e^-at) f(t) is
A F(s) (e^-at)
B F(s-a)
C F(s+a)
D F(s)/(s +a)
Que. 32 |Adj A| is equal to
A |A|^n
B |A|^(n-1)
C |A|^(n+1)
D |A^-1|
Que. 33 About the fourier series expansion ofa perodic function it can be said
that
A Even function have only a constant and cosine terms in there
FS expansion
B odd function have only sine terms in there FS expansion
C functions with half wave symmetry contain only odd harmonics
D all above the three
Que. 34 the final value of [(L^-1)(2s+1)]/[(s^4)+8(s^3)+16(s^2)+s] is
A infinity
B 2
C 1
D 0
Que. 35 The fourier transform of a Gaussian time pulse is
A uniform
B A pair of impulses
C Gaussian
D Rayleigh
Que. 36 The discrete time system described by y(n)=x(n)^2 is
A causal,linear and time varying
B causal,non-linear and time varying
C non-causal,linear and time invarying
D non-causal,non-linear and time variant
Que. 37 Which one of the following transfer functions does correspond to a non-minimum
phase system?
A s/[(s^2)+2s+1]
B (s+1)/[(s^2)+2s+1]
C (s+1)/[(s^2)+2s-1
D (s-1)/[(s^2)+2s+1]
Que. 38 The electromechanical closed loop control system has the following characteristic
equation: [(s^3)+6K(s^2)+(K+2)s+8]=0 where K is the forward gain
of the system.the condition for closed loop stability is
A K=0.528
B K=2
C K=0
D K=-2528
Que. 39 Which of the following signal is/are periodic?
A S(t)=cos2t+cos3t+cos5t
B S(t)=exp[j8(pi)t]
C S(t)=exp(-7t)sin10(pi)t
D S(t)=cos2tcos4t
Que. 40 A secound-order system has a transfer function given by G(s)=25/[(s^2)+8s+25]
If the system,initally at rest is subjected to a unit step input at t=0,the
secound peak in response will occur at
A (pi) sec
B (pi) /3 sec
C 2(pi)/3 sec
D (pi)/2 sec
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