Question

Direction: The following item consists of two statements, one labelled as ‘Statement (I)’ and the other as ‘Statement (II)’. Examine these two statements carefully and select the answers to these items using the code given below:

Statement I: Stability of a system deteriorates when integral control is incorporated into it.

Statement II: With integral control action, the order of a system increases and higher the order of the system, more the system tends to become unstable.
1. Both Statement I and Statement II are individually true and Statement II is the correct explanation of Statement I
2. Both Statement I and Statement II are individually true but Statement II is not the correct explanation of Statement I
3. Statement I is true but Statement II is false
4. Statement I is false but Statement II is true

Answer 1

Correct Answer - Option 1 : Both Statement I and Statement II are individually true and Statement II is the correct explanation of Statement I

The order of a system increases and the higher the order of the system, the more the system tends to become unstable.

With integral control action, the order of the system increases. Therefore, the Stability of a system deteriorates when integral control is incorporated into it.

Both Statement I and Statement II are individually true and Statement II is the correct explanation of Statement I

Effects of Proportional Integral (PI) controllers:

• Increases the type of the system by one
• Rise time and settling time increases and Bandwidth decreases
• The speed of response decreased i.e. transient response becomes slower
• Decreases the steady-state error and steady-state response is improved
• Decreases the stability