646 + Mcqs in Control Systems Page 13 McqOptions

601.	The relative stability of a system is given by
A.	Gain margin alone
B.	Phase margin alone
C.	Both phase and gain margins
D.	Either (a) or (b)
Answer» D. Either (a) or (b)

Discussion

602.	A lead compensator
A.	Speeds up the transient response
B.	Increases the stability margin
C.	Increases the stability margin and speeds up the transient-response.
D.	None of the above
Answer» D. None of the above

Discussion

603.	A lag compensator
A.	Speeds up the transient response of the system
B.	Improves steady state behavior of the system
C.	Improves steady state behavior and speeds up the transient response of the system
D.	Improves steady state behavior and preserves the transient response of the system
Answer» E.

Discussion

604.	Which of the following features is not associated with Nichols chart?
A.	(0 dB, -180°) point on Nichols chart represent critical Point (-1, 0)
B.	It is symmetric about -180°
C.	M loci are centred about (0 dB, -180°) point
D.	The frequency at intersection of G(j?) locus and M = +3 dB locus gives bandwidth of closed loop system
Answer» E.

Discussion

605.	The complicated shapes in the polar plots are only due to time constants in the numerator of transfer functions.
A.	True
B.	False
Answer» B. False

Discussion

606.	Lag compensation permits a high gain at low frequencies.
A.	True
B.	False
Answer» B. False

Discussion

607.	In root locus analysis the breakaway and break in points
A.	lie on the real axis
B.	Either lie on the real axis or occur in complex conjugate pairs
C.	Always occur in complex conjugate pairs
D.	None of the above
Answer» C. Always occur in complex conjugate pairs

Discussion

608.	Which of the following statements is correct for any closed loop system?
A.	All the co-efficient can have zero value
B.	All the co-efficient are always non-zero
C.	Only one of the static error co-efficient has a finite non-zero value
D.	None of the mentioned
Answer» D. None of the mentioned

Discussion

609.	Loop gain provided by the regenerative feedback makes the closed loop transfer function insensitive to G(s).
A.	True
B.	False
Answer» B. False

Discussion

610.	Which of the following are the characteristics of regenerative feedback
A.	Zero damping
B.	Stable
C.	Least sensitive to parameter variations
D.	None of the mentioned
Answer» B. Stable

Discussion

611.	Regenerative feedback is also called as_________________
A.	Negative feedback
B.	Positive feedback
C.	No feedback
D.	Negative and Positive Feedback
Answer» C. No feedback

Discussion

612.	The effect of adding feedback makes the system__________
A.	Linear
B.	Non-linear
C.	Time variant
D.	Time invariant
Answer» B. Non-linear

Discussion

613.	Feedback can cause a system that is originally stable to become___________
A.	Stable
B.	Unstable
C.	Conditionally stable
D.	Either more stable or unstable
Answer» E.

Discussion

614.	Multiple signals as input can be used in which systems:
A.	Feedback systems
B.	Non feedback systems
C.	Feedforward systems
D.	None of the mentioned
Answer» B. Non feedback systems

Discussion

615.	Feedback can always reduce the effects of noise and disturbance on system performance?
A.	True
B.	False
Answer» B. False

Discussion

616.	The closed system has higher ________ than open loop control system, this implies increased speed of response.
A.	Gain
B.	Bandwidth
C.	Frequency
D.	Speed
Answer» C. Frequency

Discussion

617.	Consider the following statements with respect to the feedback of the control systems: 1. Feedback can improve stability or be harmful to stability if it is not properly applied. 2. Feedback can always improve stability 3. In many situations the feedback can reduce the effect of noise and disturbance on system performance. 4. In general the sensitivity of the system gain of a feedback system of a parameter variation depends on where the parameter is located.
A.	1,2 and 3 only
B.	1,3 and 4 only
C.	1,2 and 4 only
D.	1,2,3 and 4 only
Answer» C. 1,2 and 4 only

Discussion

618.	Feedback control systems are:
A.	Insensitive to both forward and feedback path parameter changes
B.	Insensitive to both forward and feedback path parameter changes
C.	Less sensitive to forward path parameter changes that to feedback path parameter changes
D.	Equally sensitive to forward feedback path parameter changes
Answer» D. Equally sensitive to forward feedback path parameter changes

Discussion

619.	Feedback always increases the gain?
A.	True
B.	False
Answer» C.

Discussion

620.	Benefits of feedback:
A.	Performance of system is greater.
B.	Need for system much larger path gain and system instability.
C.	Controlled variable accurately follows the desired value
D.	Affected by parameter variations
Answer» E.

Discussion

621.	The mechanism of control of body temperature is non feedback system?
A.	True
B.	False
Answer» C.

Discussion

622.	The relationship between an input and output variable of a signal flow graph is given by the net gain between the input and output node is known as the overall______________
A.	Overall gain of the system
B.	Stability
C.	Bandwidth
D.	Speed
Answer» B. Stability

Discussion

623.	Signal flow graphs are reliable to find transfer function than block diagram reduction technique.
A.	True
B.	False
Answer» B. False

Discussion

624.	Signal flow graphs:
A.	Signal flow graphs:
B.	The equation obtained may or may not be in the form of cause or effect
C.	Arrows are not important in the graph
D.	They cannot be converted back to block diagram
Answer» B. The equation obtained may or may not be in the form of cause or effect

Discussion

625.	Loop which do not possess any common node are said to be ___________ loops.
A.	Forward gain
B.	Touching loops
C.	Non touching loops
D.	Feedback gain
Answer» D. Feedback gain

Discussion

626.	A node having only outgoing branches.
A.	Input node
B.	Output node
C.	Output node
D.	Outgoing node
Answer» B. Output node

Discussion

627.	A signal flow graph is the graphical representation of the relationships between the variables of set linear algebraic equations.
A.	True
B.	False
Answer» B. False

Discussion

628.	If the initial conditions for a system are inherently zero, what does it physically mean?
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 is stored in any of its part
D.	The system is working with zero reference input
Answer» D. The system is working with zero reference input

Discussion

629.	When deriving the transfer function of a linear element
A.	Both initial conditions and loading are taken into account
B.	Initial conditions are taken into account but the element is assumed to be not loaded
C.	Initial conditions are assumed to be zero but loading is taken into account
D.	Initial conditions are assumed to be zero and the element is assumed to be not loaded
Answer» D. Initial conditions are assumed to be zero and the element is assumed to be not loaded

Discussion

630.	A transfer function has two zeroes at infinity. Then the relation between the numerator(N) and the denominator degree(M) of the transfer function is:
A.	N=M+2
B.	N=M-2
C.	N=M+1
D.	N=M-1
Answer» C. N=M+1

Discussion

631.	In continuous data systems:
A.	Data may be continuous function of time at all points in the system
B.	Data is necessarily a continuous function of time at all points in the system
C.	Data is continuous at the inputs and output parts of the system but not necessarily during intermediate processing of the data
D.	Only the reference signal is continuous function of time
Answer» C. Data is continuous at the inputs and output parts of the system but not necessarily during intermediate processing of the data

Discussion

632.	The principle of homogeneity and superposition are applied to:
A.	Linear time invariant systems
B.	Nonlinear time invariant systems
C.	Linear time variant systems
D.	Nonlinear time invariant systems
Answer» D. Nonlinear time invariant systems

Discussion

633.	The output of the feedback control system must be a function of:
A.	Reference input
B.	Reference output
C.	Output and feedback signal
D.	Input and feedback signal
Answer» E.

Discussion

634.	Which of the following is not the feature of modern control system?
A.	Quick response
B.	Accuracy
C.	Correct power level
D.	No oscillation
Answer» E.

Discussion

635.	An object stationary or moving in a uniform motion w.r.t A will appear to be traveling in a straight path w.r.t B. This apparent path is attributed to Coriolis acceleration.
A.	True
B.	False
Answer» C.

Discussion

636.	A gantry robot consists of a manipulator mounted on an overhead system that allows movement only in ________ plane.
A.	Horizontal
B.	Inclined
C.	Vertical
D.	None of the mentioned
Answer» B. Inclined

Discussion

637.	The lagrangian is defined as:
A.	Sum of kinetic energy and hydraulic energy
B.	Mechanical energy
C.	Difference of kinetic and potential energy
D.	None of these
Answer» D. None of these

Discussion

638.	In case of DC servomotor, the back emf is equivalent to an “electric friction” which tends to:
A.	Slowly decrease the stability of the system
B.	Improve stability of the system
C.	Very rapidly decrease the stability of the system
D.	Have no effect of stability
Answer» C. Very rapidly decrease the stability of the system

Discussion

639.	Assertion (A): Servomotors have heavier rotors and lower R/X ratio as compared to ordinary motors of similar ratings. Reason (R): Servomotor should have smaller electrical and mechanical time constants for faster response.
A.	Both A and R are true and R is the correct explanation of A
B.	Both A and R are true but R is not correct explanation of A
C.	A is true but R is false
D.	A is false but R is true
Answer» E.

Discussion

640.	Gear train in the motor is used to reduce the gear ratio?
A.	True
B.	False
Answer» C.

Discussion

641.	Tachometer feedback in a D.C. position control system enhances stability?
A.	True
B.	False
Answer» B. False

Discussion

642.	Backlash in a stable control system may cause:
A.	Under damping
B.	Over damping
C.	High level oscillations
D.	Low level oscillations
Answer» E.

Discussion

643.	A synchro Transmitter is used with control transformer for:
A.	Feedback
B.	Amplification
C.	Error detection
D.	Remote sensing
Answer» D. Remote sensing

Discussion

644.	A tachometer is added to servomechanism because:
A.	It is easily adjustable
B.	It can adjust damping
C.	It reduces steady state error
D.	It converts velocity of the shaft to a proportional Dc voltage
Answer» C. It reduces steady state error

Discussion

645.	Which of the following is an example of an open loop system?
A.	Household Refrigerator
B.	Respiratory system of an animal
C.	Stabilization of air pressure entering into the mask
D.	Execution of program by computer
Answer» E.

Discussion

646.	The output of an first order hold between two consecutive sampling instants is:
A.	Constant
B.	Quadratic Function
C.	Ramp Function
D.	Exponential Function
Answer» D. Exponential Function

Discussion

Explore topic-wise MCQs in ENGINEERING SERVICES EXAMINATION (ESE).

The relative stability of a system is given by

A lead compensator

A lag compensator

Which of the following features is not associated with Nichols chart?

The complicated shapes in the polar plots are only due to time constants in the numerator of transfer functions.

Lag compensation permits a high gain at low frequencies.

In root locus analysis the breakaway and break in points

Which&nbsp;of&nbsp;the&nbsp;following&nbsp;statements&nbsp;is&nbsp;correct&nbsp;for&nbsp;any&nbsp;closed&nbsp;loop&nbsp;system?

Loop&nbsp;gain&nbsp;provided&nbsp;by&nbsp;the&nbsp;regenerative&nbsp;feedback&nbsp;makes&nbsp;the&nbsp;closed&nbsp;loop&nbsp;transfer&nbsp;function&nbsp;insensitive&nbsp;to&nbsp;G(s).

Which&nbsp;of&nbsp;the&nbsp;following&nbsp;are&nbsp;the&nbsp;characteristics&nbsp;of&nbsp;regenerative&nbsp;feedback

Regenerative&nbsp;feedback&nbsp;is&nbsp;also&nbsp;called&nbsp;as_________________

The&nbsp;effect&nbsp;of&nbsp;adding&nbsp;feedback&nbsp;makes&nbsp;the&nbsp;system__________

Feedback&nbsp;can&nbsp;cause&nbsp;a&nbsp;system&nbsp;that&nbsp;is&nbsp;originally&nbsp;stable&nbsp;to&nbsp;become___________

Multiple&nbsp;signals&nbsp;as&nbsp;input&nbsp;can&nbsp;be&nbsp;used&nbsp;in&nbsp;which&nbsp;systems:

Feedback&nbsp;can&nbsp;always&nbsp;reduce&nbsp;the&nbsp;effects&nbsp;of&nbsp;noise&nbsp;and&nbsp;disturbance&nbsp;on&nbsp;system&nbsp;performance?

The&nbsp;closed&nbsp;system&nbsp;has&nbsp;higher&nbsp;________&nbsp;than&nbsp;open&nbsp;loop&nbsp;control&nbsp;system,&nbsp;this&nbsp;implies&nbsp;increased&nbsp;speed&nbsp;of&nbsp;response.

Feedback&nbsp;control&nbsp;systems&nbsp;are:

Feedback&nbsp;always&nbsp;increases&nbsp;the&nbsp;gain?

Benefits&nbsp;of&nbsp;feedback:

The&nbsp;mechanism&nbsp;of&nbsp;control&nbsp;of&nbsp;body&nbsp;temperature&nbsp;is&nbsp;non&nbsp;feedback&nbsp;system?

Signal&nbsp;flow&nbsp;graphs&nbsp;are&nbsp;reliable&nbsp;to&nbsp;find&nbsp;transfer&nbsp;function&nbsp;than&nbsp;block&nbsp;diagram&nbsp;reduction&nbsp;technique.

Signal&nbsp;flow&nbsp;graphs:

Loop&nbsp;which&nbsp;do&nbsp;not&nbsp;possess&nbsp;any&nbsp;common&nbsp;node&nbsp;are&nbsp;said&nbsp;to&nbsp;be&nbsp;___________&nbsp;loops.

A&nbsp;node&nbsp;having&nbsp;only&nbsp;outgoing&nbsp;branches.

A&nbsp;signal&nbsp;flow&nbsp;graph&nbsp;is&nbsp;the&nbsp;graphical&nbsp;representation&nbsp;of&nbsp;the&nbsp;relationships&nbsp;between&nbsp;the&nbsp;variables&nbsp;of&nbsp;set&nbsp;linear&nbsp;algebraic&nbsp;equations.

If&nbsp;the&nbsp;initial&nbsp;conditions&nbsp;for&nbsp;a&nbsp;system&nbsp;are&nbsp;inherently&nbsp;zero,&nbsp;what&nbsp;does&nbsp;it&nbsp;physically&nbsp;mean?

When&nbsp;deriving&nbsp;the&nbsp;transfer&nbsp;function&nbsp;of&nbsp;a&nbsp;linear&nbsp;element

A&nbsp;transfer&nbsp;function&nbsp;has&nbsp;two&nbsp;zeroes&nbsp;at&nbsp;infinity.&nbsp;Then&nbsp;the&nbsp;relation&nbsp;between&nbsp;the&nbsp;numerator(N)&nbsp;and&nbsp;the&nbsp;denominator&nbsp;degree(M)&nbsp;of&nbsp;the&nbsp;transfer&nbsp;function&nbsp;is:

In&nbsp;continuous&nbsp;data&nbsp;systems:

The&nbsp;principle&nbsp;of&nbsp;homogeneity&nbsp;and&nbsp;superposition&nbsp;are&nbsp;applied&nbsp;to:

The&nbsp;output&nbsp;of&nbsp;the&nbsp;feedback&nbsp;control&nbsp;system&nbsp;must&nbsp;be&nbsp;a&nbsp;function&nbsp;of:

Which&nbsp;of&nbsp;the&nbsp;following&nbsp;is&nbsp;not&nbsp;the&nbsp;feature&nbsp;of&nbsp;modern&nbsp;control&nbsp;system?

A&nbsp;gantry&nbsp;robot&nbsp;consists&nbsp;of&nbsp;a&nbsp;manipulator&nbsp;mounted&nbsp;on&nbsp;an&nbsp;overhead&nbsp;system&nbsp;that&nbsp;allows&nbsp;movement&nbsp;only&nbsp;in&nbsp;________&nbsp;plane.

The&nbsp;lagrangian&nbsp;is&nbsp;defined&nbsp;as:

In&nbsp;case&nbsp;of&nbsp;DC&nbsp;servomotor,&nbsp;the&nbsp;back&nbsp;emf&nbsp;is&nbsp;equivalent&nbsp;to&nbsp;an&nbsp;&ldquo;electric&nbsp;friction&rdquo;&nbsp;which&nbsp;tends&nbsp;to:

Gear&nbsp;train&nbsp;in&nbsp;the&nbsp;motor&nbsp;is&nbsp;used&nbsp;to&nbsp;reduce&nbsp;the&nbsp;gear&nbsp;ratio?

Tachometer&nbsp;feedback&nbsp;in&nbsp;a&nbsp;D.C.&nbsp;position&nbsp;control&nbsp;system&nbsp;enhances&nbsp;stability?

Backlash&nbsp;in&nbsp;a&nbsp;stable&nbsp;control&nbsp;system&nbsp;may&nbsp;cause:

A&nbsp;synchro&nbsp;Transmitter&nbsp;is&nbsp;used&nbsp;with&nbsp;control&nbsp;transformer&nbsp;for:

A&nbsp;tachometer&nbsp;is&nbsp;added&nbsp;to&nbsp;servomechanism&nbsp;because:

Which&nbsp;of&nbsp;the&nbsp;following&nbsp;is&nbsp;an&nbsp;example&nbsp;of&nbsp;an&nbsp;open&nbsp;loop&nbsp;system?

The&nbsp;output&nbsp;of&nbsp;an&nbsp;first&nbsp;order&nbsp;hold&nbsp;between&nbsp;two&nbsp;consecutive&nbsp;sampling&nbsp;instants&nbsp;is:

Which of the following statements is correct for any closed loop system?

Loop gain provided by the regenerative feedback makes the closed loop transfer function insensitive to G(s).

Which of the following are the characteristics of regenerative feedback

Regenerative feedback is also called as_________________

The effect of adding feedback makes the system__________

Feedback can cause a system that is originally stable to become___________

Multiple signals as input can be used in which systems:

Feedback can always reduce the effects of noise and disturbance on system performance?

The closed system has higher ________ than open loop control system, this implies increased speed of response.

Feedback control systems are:

Feedback always increases the gain?

Benefits of feedback:

The mechanism of control of body temperature is non feedback system?

Signal flow graphs are reliable to find transfer function than block diagram reduction technique.

Signal flow graphs:

Loop which do not possess any common node are said to be ___________ loops.

A node having only outgoing branches.

A signal flow graph is the graphical representation of the relationships between the variables of set linear algebraic equations.

If the initial conditions for a system are inherently zero, what does it physically mean?

When deriving the transfer function of a linear element

A transfer function has two zeroes at infinity. Then the relation between the numerator(N) and the denominator degree(M) of the transfer function is:

In continuous data systems:

The principle of homogeneity and superposition are applied to:

The output of the feedback control system must be a function of:

Which of the following is not the feature of modern control system?

A gantry robot consists of a manipulator mounted on an overhead system that allows movement only in ________ plane.

The lagrangian is defined as:

In case of DC servomotor, the back emf is equivalent to an “electric friction” which tends to:

Gear train in the motor is used to reduce the gear ratio?

Tachometer feedback in a D.C. position control system enhances stability?

Backlash in a stable control system may cause:

A synchro Transmitter is used with control transformer for:

A tachometer is added to servomechanism because:

Which of the following is an example of an open loop system?

The output of an first order hold between two consecutive sampling instants is: