## Viva Questions on Systems

Viva Questions on Systems, Short Questions on Systems, Continuous-Time System, Discrete-Time System, Engineering Viva Questions, Signal & Systems Viva Questions, Short Questions on Signal & Systems,

Viva Questions on Signals

### Short Questions and Answers

Q.1. Define system.

Ans. A system is defined as a physical device that generates a response, or output signal, for a given input signal.

Q.2. Define (i) Continuous-time system (ii) Discrete-time system.

Ans.

Continuous-Time System: A continuous-time system is one that operates on a continuous-time input signal and produces a continuous-time output signal.

Discrete-Time System: A discrete-time system is one that operates on discrete-time input signals and produces a discrete-time input signal.

Q.3. What is the classification of the system?

Ans.

1. Static and dynamic systems.
2. Time-variant and time-invariant systems.
3. Linear and non-linear systems.
4. Stable and unstable systems.
5. Causal and non-causal system.

Q.4. Define linear-time invariant system.

Ans. An LTI system is one that possesses two basic properties, linearity and time-invariance.

Linearity: An LTI system obeys the superposition principle which states that the output of the system to a weighted sum of inputs is equal to the weighted sum of the outputs corresponding to each of the individual inputs.

Time invariance: If the input-output relation of a system does not vary with time, then the system is said to be time-invariant

Q.5. Is the system y(t) = y(t – 1) + 2t y(t – 2) time-invariant?

Ans. No. The system is time-variant. The coefficient 2t of the difference equation is a function of time.

Q.6. Define static and dynamic systems.

Ans.

Static system: A static or memoryless system is a system whose output at any instant depends only on the input value at that instant.

Dynamic system: A dynamic is one in which the output at any instant depends on past or future values of inputs.

Q.7. Define a causal system.

Ans. A system is said to be causal if the output of the system at any time depends only on the present and past inputs, but does not depend on future inputs.

Q.8. What is a stable system?

Ans. Any relaxed system is said to be bounded input-bounded output (BIRO) stable if and only if every bounded input yields a bounded output.