Solved problems on MATLAB for engineering students

This article contains solved problems on MATLAB for engineering students. The first set of problems includes calculations for volume of rainwater collected, while the second set includes calculations for solar cell current and a matrix problem. Each problem includes step-by-step solutions and MATLAB code.

Set 1
Problem 1
clc
a = [ 4.5 4.61 3.26 1.46 0.7 0.16 0 0.06 0.12 0.12 1.12 3.16 4.56 ] ;
display ('The data in inches:');
display ( a );
b = a * 0.0254;
display ('The data in meters:');
display ( b );
s=0;
for (i= 1:12)
s = s + b(i);
end
v = s * 40.25 * 1000000;
vl = v * 1000;
vg = vl/3.78;
display (' Volume in litres:');
display (vl);
display (' Volume in gallons:');
display (vg);
vtl = s * 10 * 30 * 0.3048 * 0.3048 *1000;
vtg = vtl / 3.78;
display ('amount of rain water collected by the system in a year in
litres:');
display (vtl);
display ('amount of rain water collected by the system in a year in
gallons:');
display (vtg);
du = [ 8.8 10 8.2 0.7 1.2 4 10.8 1.6 ] ;
display ('Daily usage in gallons: ');
display (du);
dl = du * 3.78 ;
display ('Daily usage in litres: ');
display (dl);
dy = dl * 365 ;
display ('Yearly water usage in litres for each activity: ');
display (dy);
s1=0;
for (j= 1:8)
s1 = s1 + dl(j);
end
yu = s1 * 365 ;
display (' Yearly Water usage of 1 person');
display (yu);

Output:
The data in inches:
a =
Columns 1 through 12
4.5000 4.6100 3.2600 1.4600 0.7000 0.1600 0 0.0600 0.1200 0.1200 1.1200
3.1600
Column 13
4.5600
The data in meters:
b =
Columns 1 through 12
0.1143 0.1171 0.0828 0.0371 0.0178 0.0041 0 0.0015 0.0030 0.0030 0.0284
0.0803
Column 13
0.1158
Volume in litres:

vl =
1.9701e+10
Volume in gallons:
vg =
5.2118e+09
amount of rain water collected by the system in a year in litres:
vtl =
1.3642e+04
amount of rain water collected by the system in a year in gallons:
vtg =
3.6089e+03
Daily usage in gallons:
du =

8.8000 10.0000 8.2000 0.7000 1.2000 4.0000 10.8000 1.6000
Daily usage in litres:
dl =
33.2640 37.8000 30.9960 2.6460 4.5360 15.1200 40.8240 6.0480
Yearly water usage in litres for each activity:
dy =
1.0e+04 *
1.2141 1.3797 1.1314 0.0966 0.1656 0.5519 1.4901 0.2208
Yearly Water usage of 1 person
yu =
6.2500e+04

Set 1
Problem 2
clc
vs = 0.01;
c = 0.00001;
r1 = 10000;
r2 = 1000;
r3 = 100;
t = 0 : 0.001 : 0.2;
x1 = -t/(r1*c);
v1 = vs * ( 1 - exp ( x1 ));
plot (t,v1,'m');
hold on;
x2 = -t/(r2*c);
v2 = vs * ( 1 - exp ( x2 ));
plot (t,v2,'g');
hold on;
x3 = -t/(r3*c);
v3 = vs * ( 1 - exp ( x3 ));
plot (t,v3,'c');
hold on;
legend ('r1=10k','r2=1k','r3=0.1k');
title('Output Voltage versus time');
hold off;
grid on;
Output:

Set 2
Problem 1
clc
ilight = 0.5;
idark = 0.0000006;
vt = 0.026;
x = 0.3 / 0.026 ;
p = 1;
s=1;
for (i = 1:4)
p = p * x;
q = factorial(i);
r = p / q;
s = s + r;
end
isolar = ilight + idark - (idark * s);
display('Till 5 terms:');
display (isolar);
p1 = 1;
s1=1;
for (j = 1:19)
p1 = p1 * x;
q1 = factorial(j);
r1 = p1 / q1;
s1 = s1 + r1;
end
isolar = ilight + idark - (idark * s1);
display('Till 20 terms:');
display (isolar);
Output:
Till 5 terms:
isolar =
0.4994
Till 20 terms:
isolar =
0.4394

Set 2
Problem 2
clc
c = [ 0.1 , 0 , 0 , 0 ; 0.75 , 0.05 , 0 , 0 ; 0 , 0.9 , 0.05 , 0;0 , 0 ,
0.9 , 0.05 ];
y = [ 500 ; 400 ; 300 ; 280 ];
b = [ 1000 ; 200 ; 0 ; 0];
for k = 1:10
y = c*y + b;
display (y);
s = sum(y);
bar (k,s);
hold on;
end
Output
y =
1050
595
375
284
y =
1.0e+03 *
1.1050
1.0173
0.5543
0.3517

y =
1.0e+03 *
1.1105
1.0796
0.9432
0.5164
y =
1.0e+03 *
1.1110
1.0869
1.0188
0.8747
y =
1.0e+03 *
1.1111
1.0876

1.0291
0.9607
y =
1.0e+03 *
1.1111
1.0877
1.0303
0.9742
y =
1.0e+03 *
1.1111
1.0877
1.0305
0.9760
y =
1.0e+03 *

1.1111
1.0877
1.0305
0.9762
y =
1.0e+03 *
1.1111
1.0877
1.0305
0.9762
y =
1.0e+03 *
1.1111
1.0877
1.0305
0.9762