The system shown in the figure given below is

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The system shown in the figure given below is

1. stable
2. unstable
3. conditionally stable
4. stable for input u₁, but unstable for input u₂

Correct Option: D

Transfer function for u₁

TF₁ =

(s - 1) / (s + 2)

=

(s - 2)

1 +

s - 1

.

1

(s + 3)

s + 2

s - 1

TF₂(s) =			1
			s - 1

	1 +		1		.			s - 1
			s - 1							s + 2

=	1
	(s + 3)(s - 1)

Hence unstable, as it has pole at right side of s-plane.