Question

Which of the following statements are true for a type-Il system having unity negative feedback?
(Positional error constant Kp is equal to zero.
(ii) Acceleration error constant ka is equal to infinite.
(iii) Steady state error to a unit step displacement input is equal to one.
(i) and (iii)
None of these
с
(i), (i) and (lli)
(1) and (IN)​

Answer 1

Answer:

I hope give answer is right (i), (i) and (iii)

Answer 2

Answer:

(c) None of these

Explanation:

Let the type 1 system be assumed as:

$G(s)=\frac{1}{s(1+s \tau)}$

Positional error constant

$k_{p}=\lim _{s \rightarrow 0} \frac{1}{s(1+s \tau)}=\infty$

Statement 1 is wrong.

Acceleration error constant

$k_{a}=\lim _{s \rightarrow 0} \frac{s^{2}}{s(1+s \tau)}=0$

Statement $\mathbf{2}$ is incorrect.

Given input is Unit step

$e_{s s}=\frac{A}{1+k_{p}}$

We have calculated  $k_{p}$ and the value is $\infty$

$e_{s s}=\frac{1}{1+\infty}=0$

Statement 3 is incorrect.

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