Machine Dynamics

Open-Loop Transfer Function

Question 1
Marks : +2 | -2
Pass Ratio : 100%
In an open loop control system
Output is independent of control input
Output is dependent on control input
Only system parameters have effect on the control output
None of the mentioned
Explanation:
When the input to a system is independent of the output from the system, then the system is called an open-loop or unmonitored system.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
A control system in which the control action is somehow dependent on the output is known as
Closed loop system
Semiclosed loop system
Open system
None of the mentioned
Explanation:
When output of a system is measured and is continuously compared with the required value, then it is known as closed-loop or monitored system.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
Which of the following is an open loop control system ?
Field controlled D.C. motor
Ward leonard control
Metadyne
Stroboscope
Explanation:
In field control D.C. motor, the input is dependent of the output. So it is an open loop control system.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
A good control system has all the following features except
good stability
slow response
good accuracy
sufficient power handling capacity
Explanation:
Repose is not included in a good control system.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
In open loop system
the control action depends on the size of the system
the control action depends on system variables
the control action depends on the input signal
the control action is independent of the output
Explanation:
When the input to a system is independent of the output from the system, then the system is called an open-loop or unmonitored system.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
The following has tendency to oscillate.
Open loop system
Closed loop system
Both (a) and (b)
Neither (a) nor (b)
Explanation:
Both open loop system and closed loop system have the tendency to oscillate.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
For open control system which of the following statements is incorrect ?
Less expensive
Recalibration is not required for maintaining the required quality of the output
Construction is simple and maintenance easy
Errors are caused by disturbances
Explanation:
Most measuring instruments are open-loop control systems, as for the same input signal, the readings will depend upon things like ambient temperature and pressure.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
In closed loop control system, with positive value of feedback gain the overall gain of the system will
decrease
increase
be unaffected
none of the mentioned
Explanation:
In closed loop control system, the output is measured and through a feedback transducer, it is sent to an error detector which detects any error in the output from the required value thus adjusting the input in a way to get the required output.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Which of the following statements is not necessarily correct for open control system ?
Input command is the sole factor responsible for providing the control action
Presence of non-linearities causes malfunctioning
Less expensive
Generally free from problems of non-linearities
Explanation:
When the input to a system is independent of the output from the system, then the system is called an open-loop or unmonitored system. It is also called as a calibrated system. Most measuring instruments are open-loop control systems, as for the same input signal, the readings will depend upon things like ambient temperature and pressure.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
A car is running at a constant speed of 50 km/h, which of the following is the feedback element for the driver ?
Clutch
Eyes
Needle of the speedometer
Steering wheel
Explanation:
The needle of the speedometer is only the indicator of the speed and to keep the speed constant, the driver has to maintain the speed of 50 km/h.