PRACTICAL MATLAB® FOR ENGINEERS PRACTICAL MATLAB

166 Practical MATLAB® Applications for Engineers

and

vt V it RL()
 11 ()* eq

where

RRRRR

RR

eq1 (^1231) RR
23
23
8
63
63


 82 10




(||) *


and
 1 = L/Req1 = 10 H/10
= 1 s
At t = t 1 = 2 s, the current i 1 (t 1 ) is at its maximum as given by
Iit
V
R
11 e
1
212 1
max
() /



()
0
eq
 
At t = 2 s, the switch moves back to position a, where it remains indefi nitely. The branch
currents would then be given by
it I e
11 ()
max()/tt^12 
it
R
RR
2 3 it
23
()
 1 ()
it
R
RR
3 2 it
23
()
 1 ()
and
vt it RL()
12 () eq
where
RRRRR
RR
eq 2 (^4234) RR
23
23
18
63
63


 18 2 20




(||)


and
 2 = L/Req2 = 10 H/20
= 0.5 s
MATLAB Solution
% Script file: analysis _ exam
V=100; R1 = 8; R2 =3; R3 =6; R4 =18; L=10; % circuit elements.
Req1 = R1+(R2R3)/(R2+R3);