Which of the following systems is stable?a)y(t) = log(x(t))b)y(t) = si...
Stability implies that a bounded input should give a bounded output. In a,b,d there are regions of x, for which y reaches infinity/negative infinity. Thus the sin function always stays between -1 and 1, and is hence stable.
View all questions of this testWhich of the following systems is stable?a)y(t) = log(x(t))b)y(t) = si...
Stability of Systems
Stability is an important property of any system, and it refers to the ability of the system to remain bounded and not diverge to infinity. A stable system is one that will always return to its equilibrium state after being subjected to a disturbance. There are different ways to classify the stability of a system, but the most common one is based on the concept of boundedness.
Types of Stability
There are three types of stability:
1. BIBO Stability (Bounded-Input Bounded-Output Stability): this type of stability ensures that if the input signal to the system is bounded, then the output signal must also be bounded.
2. Asymptotic Stability: this type of stability ensures that the system returns to its equilibrium state after being subjected to a disturbance.
3. Lyapunov Stability: this type of stability ensures that the system does not diverge to infinity.
Stability of the given systems
a) y(t) = log(x(t)): This system is not BIBO stable as the logarithmic function is unbounded. It can cause the output to become unbounded even if the input signal is bounded.
b) y(t) = sin(x(t)): This system is asymptotically stable as the sinusoidal function is bounded, and it will always return to its equilibrium state (zero) after being subjected to a disturbance.
c) y(t) = exp(x(t)): This system is not BIBO stable as the exponential function is unbounded. It can cause the output to become unbounded even if the input signal is bounded.
d) y(t) = tx(t): This system is not BIBO stable as the output can become unbounded if the input signal is unbounded.
Conclusion
The only stable system among the given options is y(t) = sin(x(t)) as it is asymptotically stable. The other systems are not stable as they can cause the output to become unbounded even if the input signal is bounded.