CHOOSE THE
CORRECT ANSWER
1. Feedback control systm are,
a.
Insensitive
to feedback path and forward path parameters change
b.
Less
senative to feedback path parameter changes than to forward path parameters
changes
c.
Less
sensitive to feedback path parameter changes than to forward path parameters
changes
d.
Equally
2. Pick up the correct sentence
among the following which represent the good characterstics of a system
a.
Sensitive
to parameter variation
b.
Insensitive
to input commands
c.
Neither
sensitive to parameter variation nor to input commands
d.
Insensitive
to parameter variation about sensitive to input commands
3. If a system has inherently zero
intial conditions then physically it means
a.
The
system is at rest but stores energy
b.
The system is working but does not store
energy
c.
The
system is at rest (or) no energy stored in any of its parts
d.
The
system is working with zero reference input
4. The system described by the
equation y=k1x+k2 for k1>0 k2>0
represents,
a.
Linear
b.
Non-linear
c.
Time
varying
d.
Dynamic
5. The basic elements of a
mechanical rotational systems are
a.
Moment
of inertia
b.
Dash-pot
c.
Spring
d.
All
the above
6. The basic elements of a
mechanical translation system are
a.
Mass
b.
Spring
c.
Dash-pot
d.
All
the above
7. A few names of synchro’s are
a.
Selsyn
b.
Autosyn
c.
Telesyn
d.
All
the above
8. Block diagram can be used for,
a.
Only
linear systems
b.
Only
non-linear systems
c.
Both
linear and non-linear systems
d.
Time-invariant
as well as time-varying systems
9. A node which has both incoming
and out going branches is,
a.
Sink
b.
Source
c.
Mixed
node
d.
None
10. Laplace transform of an impulse
function is given by,
a.
One
b.
Zero
c.
None
of the above
d.
I/S
11. The transient response of a system
depends on,
a.
Only
on the inputs applied
b.
Only
on the system poles
c.
Both
the system poles and inputs
d.
None
of the above
12. If the value of time constant is
large, then it corresponds to the system
a.
Faster
b.
Under
damped
c.
Sluggish
d.
Over
damped
13. The velocity error constant is
given by
a.
Lims-0
SG(S)H(S)
b.
Lims-0
S2G(S)H(S)
c.
Lims-0
G(S)H(S)
d.
None
of the above
14. The order of a control system
with an integral control,
a.
Decrease
b.
Increases
c.
Remains
unaffected
d.
None
15. The system that has non-repeated
poles on jw-axis is a,
a.
Conditionally
stable
b.
Stable
c.
Un-stable
d.
Marginally
stable
16. Integrator’s are,
a.
Marginally
stable
b.
Absolutely
method
c.
Conditionally
stable
d.
None
of these
17. The ROUTH stability critirion for
testing the stability is an,
a.
Graphical
method
b.
Alzebric
method
c.
Both
d.
None
18. The root locus technique is an,
a. Graphical method
b. Alzebric method
c. Both
d. None
19. The root locus technique is used
to study,
a.
Absolute
stability of system
b.
Relative
stability of system
c.
Both
d.
None
of these
20. An octave is the range of frequencies given
by,
a.
W2=2w1
b.
W2=8w1
c.
W2=10w1
d.
W2=14.14w1
21. Db’s are unis of
a.
20logeG(jw)
b.
G(jw)
c.
20log10G(jw)
d.
10log10G(jw)
22. A unity feedback system has
G(s)=100(s+2)/(s2(s+1)(s2+2s+1)). The slope of the low
frequency asymptote is
a.
-20db/decade
b.
-80db/decade
c.
-40db/decade
d.
80db/decade
23. The log magnitude of a system
with transfer function e-0.1 is,
a.
Unity
b.
-20
c.
-46.05
d.
0
24. If a system consists of oe zero
and five poles the final slope of the magnitude plot is
a.
80db/decade
b.
-80db/decade
c.
-60db/decade
d.
60db/decade
25. In a magnitude plot of a system
the slope changed by +20dbs at w=10rad/sec. The corresponding factor in the
loop transfer function is,
a.
(1+0.1jw)
b.
1/(1+0.1jw)
c.
10/jw
d.
10jw
26. For a large gain margin or phase
margin the system is
a.
Stable
b.
Sluggish
c.
Both
d.
None
27. Addition of a zero at origin to a
transfer function results in rotation of the polar plot through an angle
of at both 0 and infinite
frequencies is,
a.
-900
b.
0
c.
1800
d.
900
28. A unity feedback system is
G(s)=1/(1+10s). For the inverse polar plot of this system, the magnitude and
phase angle at zero frequency are,
a.
1,0
b.
0,1,0
c.
Infinite,
900
d.
Infinite,
-900
29. The loop transfer function of a
system is 1/(s2(1+s)(1+10s)(1+100s))
a.
–ve
real, +jw, +ve real
b.
Only
+ve imaginary
c.
+ve
jw and +ve real
d.
Only
–ve imaginary
30. The loop transfer function of a
system is G(s)H(s)=1/(1+s). The magnitude and phase angle at infinite frequency
are,
a.
0,
n/2
b.
0,-n/2
c.
Infinite,
-900
d.
Infinite,
900
31. The polar plot of a system passes
through the point (-1+j0). The GM is
a.
-1db
b.
<1db
c.
1db
d.
0db
32. Adding a pole at s=0 to a loop transfer
function will,
a.
Not
affect the stability of closed loop system
b.
Increase
the stability of closed loop system
c.
Reduce
the stability of the closed loop system
d.
None
of these
33. Addition of zeros to the loop
transfer function affects the closed loop stability in the following manner
a.
It
is improved
b.
It
is reduced
c.
It
is not affected
d.
The
exact effect depends on the loop transfer function
34. In control system design GM and
PM are usually provided to
a.
Make
the system respond fast
b.
Account
for the uncertainties in the system
c.
Reduce
the overshoot in the stop response
d.
Reduce
the steady state offers
35. In the frequency domain design if
the open loop gain is increased the gain cross over frequency w1 and
phase cross over w2 on the bode plots get affected in the following
manner
a.
Both
w1, w2 move to right
b.
Both
w1, w2 remain constant
c.
W2
is constant while w1 moves to right
d.
W1
moves to right while w2 remains constant
36. If the gain is increased the
magnitude plot of bode plot,
a.
Shifts
up
b.
Shifts
down
c.
Does
not get affected
d.
Gets
totally changed and shifts down
37. For a lead componesator the value
of ‘a’ should be,
a.
1<a<0
b.
1
c.
0<a<1
d.
0
38. With a lead compensator the rise
time of the system will,
a.
Increase
to the extent which depends to the loop transfer function of the system
b.
Increase
c.
Remain
same
d.
Decrease
39. In a lag compensator the
sensitivity function is greater than unity. This is true for,
a.
Frequency
equal to bandwidth
b.
Entire
frequency range
c.
Frequencies
lesser than bandwidth
d.
Frequencies
greater than bandwidth
40. In the time domain, the phase lag
control generally will,
a.
Decrease
rise time and setting time
b.
Increase
rise time and setting time
c.
Both
increase and decrease setting time
d.
Decrease
rise time and increase setting time
41. The typical value of b choosen in
the lag compensator is usually,
a.
0
b.
0.1
c.
10
d.
Infinite
42. When a sinusoidal signal is
appied to a lag network, phase lag and phase lead occur in the output in and frequency regions
a.
Low
and low
b.
Low
and high
c.
High
and high
d.
High
and low
43. By using lag lead compensation
the order of the system will,
a.
Become
doubled
b.
Increase
by one
c.
Remain
same
d.
Increase
by two
44. The phase lead portion of a lead
lag compensator is used in
rise time and
bandwidth
a.
Smaller,
higher
b.
Smaller,
smaller
c.
Higher,
higher
d.
Higher,
smaller
45. A PD controller,
a.
Decrease
both BW and rise time
b.
Increase
both BW and rise time
c.
Increases
BW and reduces rise time
d.
Decreases
BW and increases rise time
46. A PI controller
a.
Increase
rise time and decreases BW
b.
Increase
both BW and rise time
c.
Increase
BW and reduces rise time
d.
Decreases
BW and increases rise time
47. A PID controller
a.
Improves
both steady state but transient response
b.
Improves
steady state but transient response is not affected
c.
Improves
transient state but steady state is not affected
d.
Does
not affect either steady station or transient respone
FILL IN THE BLANKS
- 1. Sprinkler is an example of open-loop system.
- 2. The input quantity is also known as excitation or command signal
- 3. The output quantity is also known as response
- 4. An a.c servo meter is 2-phase induction meter
- 5. A signal flow graph is applicable only to linear systems
- 6. The synchro meter transmitter and receiver are combinedly known as synchro pair
- 7. Impulse signal is a signal whose value is zero at t-0, where its magnitude is infinite
- 8. Unity is the area under a unit-impulse function
- 9. The steady state error of a control system due to derivation feedback control gets increased
- 10. Root locus technique applied to both multiple loop system
- 11. The zero input stability is also known as asymptotic stability
- 12. The stability is the important characteristic of a transient response
- 13. Bandwidth is inversely proportional to input frequency
- 14. An all pass system has pole zero pattern anti symmetric about imaginary axis
- 15. Corner frequency is also called as break frequency
- 16. Nyquist stability criterion is used to determine closed loop stability
- 17. If a real pole is added to loop transfer function then only at infinite frequency
- 18. A lead compensator is a high pass filter
- 19. In a lead network the noise immunity is low
- 20. The PI controller increases the type of the system by one
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