SAMPLE QUESTIONS OF SNS (Signal & System)
SHORT QUESTIONS: (ALL ARE COMPULSORY)
- Define continuous-time signal.
A continuous-time signal is a quantity of interest that depends on an independent variable, where we usually think of the independent variable as time. Two examples are the voltage at a particular node in an electrical circuit and the room temperature at a particular spot, both as functions of time.
2. Define Signal.
In electronics, a signal is an electric current or electromagnetic field used to convey data from one place to another. The simplest form of signal is a direct current (DC)
3. Define system.
A set of connected things or parts forming a complex whole is called as system.
4. What are the major classifications of the signal?
1. Discrete signal 2. continous signal 3. Non continous signal 4. periodic signal 5. Non periodic signal.
5. State Properties of Convolution .
1. commutative 2. associative 3. distributive 4. shifting property etc.
6.What is DFT ?
DFT stands for discrete fourier transform. it converts a finite list of equally spaced samples of a function into the list of coefficients of a finite combination of complex sinusoidal.
7. What are the applications of correlation?
correlation is used in radar,sonar,digital communication geology etc. It is of two types: a. cross correlation b. auto correlation
8. What Are the classification of continuous time signals? Name them.
1. deterministic and non deterministic signal.
2. periodic and non periodic signal
3. even and odd signal
4. energy and power signal
5. causal and non causal signal
9. Give some examples of causal signal?
A signal is said to be causal,if it is defined for t>=0. examples are: step signal,unit step signal,exponential signal.
10. Give some examples of non causal signal.
exponential signal , complex exponential signal
11. What is amplitude scaling and time scaling?
The amplitude scaling is performed by multiplying the amplitude of the signal by constant. similarly time scaling is performed by multiplying the variable time by constant.
12. What is unit delay element ?
The unit delay element delay the input signal passing through it by one sample.
13. classify discrete time signal?
1. static and dynamic system
2. causal and non causal system
3. time invariant and time variant signal
4. linear and non linear signal
5. stable and unstable signal.
14. State superposition theorem.
“The response of the system to a weighted sum of signals will be equal to the corresponding weighted sum of the response i.e. output of the system to each of the individual system.” otherwise system will be non linear.
15. How the analog to digital conversion takes place. name all the steps involved.
A/D conversion takes place in three steps: