# Electronics and Communication Engineering - Signals and Systems - Discussion

Discussion Forum : Signals and Systems - Section 1 (Q.No. 1)
1.
What about the stability of system in
system is stable
unstable
stable at 0.4
cant say
Explanation:

ROC include the unit circle hence it is stable.

Discussion:
49 comments Page 5 of 5.

Arun Kumar Gupta said:   9 years ago
Without ROC one can't say that system is stable or not.

Shamsheer said:   10 years ago
ROC is |Z|>2 and .4<|Z|<4/3.

Why everyone are concerned with pole Z=2?

Manan said:   10 years ago
According to me system is unstable.

Shivanand jaiswal said:   10 years ago
roc of given problem z>2 and z>0.4 so intersection of this will be z>2 that is outside the unit circle tending to infinite this is an casual system but not stable.

Sathiya (ponds) said:   10 years ago
The pole Z=2 lies outside the unitcircle. The ROC is not mentioned in this question so the system is unstable.

Ajay kumar sharma said:   10 years ago
Pole doesn't lies b/w the circle so the system is not stable.

Raam said:   10 years ago
One of the pole z=2 lies outside the unit circle, so the system is unstable.

S.p.Bharath said:   10 years ago
The pole Z=2 lies outside the unity circle. Then how can we say it as stable ?

Iman said:   10 years ago
I think the ROC would have to be mentioned in the question to answer the question. Like 0.4 < |z| < 2.