The document contains 6 MATLAB programs that generate Nyquist plots for different transfer functions. Each program calculates the numerator and denominator polynomials, calls the nyquist function to generate the plot, and may include additional commands like clc, clear all, clf, grid on, and axis to clean the workspace and formatting. The output of each program is a Nyquist plot.

1. Name of exp: nyquist plot using matlab for following system.
Program: G(s) =
10
( 𝑠+1)( 𝑠+2)(𝑠+3)
clc
clear all
clf
num=[0 10];
a=[1 1];
b=[1 2];
c=[1 3];
g=conv(a,b);
den=conv(g,c);
nyquist(num,den);
grid on
output:

2. Program: G(s) =
6(𝑠+2)
𝑠2 ( 𝑠+3)(𝑠+4)
clc
clear all
clf
num=6*[1 2];
a=[1 0];
n=[1 0];
b=[1 3];
c=[1 4];
g=conv(a,b);
m=conv(g,c);
den=conv(g,m);
nyquist(num,den);
axis([-.6 0 -.1 .1])
grid on
output:

3. Program:
clc
clear all
clf
a=[-1 -1;6.5 0];
b=[1 1;1 0];
c=[1 0;0 1];
d=[0 0;0 1];
nyquist(a,b,c,d);
grid on
output:

4. Program: G(s) =
𝑠2
+3𝑠+1
𝑠3 +1.2𝑠2 +2𝑠+1
clc
clear all
num=[1 3 1];
den=[1 1.2 2 1];
w=1:0.001:100;
[re im w]=nyquist(num,den,w);
plot(re,im)
grid on
output:

5. Program: G(s) =
5𝑠 +40
( 𝑠+4)(𝑠+3)
clc
clear all
num=[5 40];
den=[1 7 12];
w=1:0.001:100;
[re im w]=nyquist(num,den,w);
plot(re,im)
grid on
output:

6. Program: G(s) =
10(𝑠+1)
𝑠( 𝑠+6)( 𝑠+2) 𝑠(𝑠+5)
clc
clear all
clf
num=10*[1 2];
a=[1 0];
n=[1 6];
b=[1 2];
c=[1 5];
g=conv(a,b);
m=conv(n,c);
den=conv(g,m);
nyquist(num,den);
axis([-1.2 .6 -1.2 1.2])
grid on
output: