Anna University Coimbatore 2008 B.E Electrical and Electronics Engineering Control system QB unit 1 - Question Paper

F = M d2x /dt2


54. Write the force balance formula of ideal dashpot element .

F = B dx /dt

55. Write the force balance formula of ideal spring element .

F = Kx

56.Distinguish ranging from open loop and closed loop system

Open loop Closed loop
1.Innaccurate

2.Simple and economical

3.The modifications in output due to external disturbance are not corrected

4.They are generally stable Accurate

Complex and costlier

The modifications in output due to external disturbances are corrected automatically

Great efforts are needed to design a stable system


57.What is servomechanism?

The servomechanism is a feedback control system in which th output is mechanical position (or time derivatives of position velocity and acceleration,)


58.Why is negative feedback invariably preferred in closed loop system?

The negative feedback outcomes in better stability in steady state and rejects any disturbance signals.
59.What is transient response
The transient response is the response of the system when the system modifications from 1 state to a different.
60.What is steady state response.
The steady state response is the response of the system when it approaches infinity.
61.What is an order of a system.
The order of asystem is the order of the differential formula governing the system.The order of the system can be found from the transfer function of the provided system.
62.Define Damping ratio.
Damping ratio is described as the ratio of true damping to critical damping.
63.List the time domain specifications.
The time domain specifications are
i.Delay time
ii.Rise time
iii.Peak time
iv.Peak overshoot
64.Define Delay time.
The time taken for response to reach 50% of final value for the very 1st time is delay time.
65.Define Rise time.
The time taken for response to raise from 0% to 100% for the very 1st time is rise time.
66.Define peak time.
The time taken for the response to reach the peak value for the 1st time is peak time.
67.Define peak overshoot.
Peak overshoot is described as the ratio of maximum peak value measured from the Maxmium value to final value
68.Define Settling time.
Settling time is described as the time taken by the response to reach and stay within specified fault
69.What is the need for a controller?
The controller is given to replace the fault signal for better control action
70.What are the various kinds of controllers.

Earning:   Approval pending.