Causal and non causal signals examples

1. What are causal and non causal signals?
2. What is non causal system with example?
3. What are the examples of causal system?
4. Which of the following signals is non causal?

What are causal and non causal signals?

A causal system is one whose output depends only on the present and the past inputs. A noncausal system's output depends on the future inputs. In a sense, a noncausal system is just the opposite of one that has memory. How can a real-world system be noncausal?

What is non causal system with example?

The non-causal systems can generate an output before the input is given, hence they are also known as anticipative systems. The non-causal systems do not exist in real time. Also, these systems are not physically realisable. The image processing systems are the examples of noncausal systems.

What are the examples of causal system?

a) y(t)=x(t)

Here, the signal is only dependent on the present values of x. For example if we substitute t = 3, the result will show for that instant of time only. Therefore, as it has no dependence on future value, we can call it a Causal system.

Which of the following signals is non causal?

y(t) = x(t) + 2 x(3 – t); it is non-causal as the output is dependent on future inputs..