# Chapter - 13 : PASSIVE CIRCUITS DEVICES¶

## Ex 13.4 Pg 248¶

In [1]:
from __future__ import division

R1min=2.7#
R2min=5.1#
Rmin=R1min+R2min#
R1max=3.3#
R2max=6.9#
Rmax=R1max+R2max#
a=9-Rmin#
b=Rmax-9#
tolerance=b/9#
Reqmin=(R1min*R2min)/(R1min+R2min)#
print "Reqmin=",Reqmin,'ohm'
Reqmax=(R1max*R2max)/(R1max+R2max)#
print "Reqmax=",Reqmax,'ohm'
R1N=3#
R2N=6#
Req=(R1N*R2N)/(R1N+R2N)#
print "Req=",Req,'ohm'
minval=Reqmin#
maxval=Reqmax#
maxchng=0.235#
t=(maxchng/2)*100#
print "t=",t,'%'

Reqmin= 1.76538461538 ohm
Reqmax= 2.23235294118 ohm
Req= 2.0 ohm
t= 11.75 %


## Ex 13.5 Pg 248¶

In [2]:
from __future__ import division
from math import pi
N=150#
mur=3540#
mu0=4*pi*10**-7#
l=0.05#
A=5*10**-4#
L=(mur*mu0*A*N*N)/l#
print "L=",L,"H"

L= 1.00091141943 H


## Ex 13.6 Pg 249¶

In [5]:
from math import sqrt
from __future__ import division

#e.g 13.6
L1=40*10**-6#
L2=80*10**-6#
M=11.3*10**-6#
k=M/sqrt(L1*L2)#
print "k=",k

k= 0.199757665685


## Ex 13.7 Pg 250¶

In [6]:
from __future__ import division
from math import pi
Q=90#
L=15*10**-6#
f=10*10**6#
R0=(2*pi*f*L)/Q#
print "R0=",R0,'ohm'

R0= 10.471975512 ohm


## Ex 13.8 Pg 251¶

In [7]:
from __future__ import division
A=0.04#
d=0.02#
e0=8.85*10**-12#
er=5.0#
C=(e0*er*A)/d#
print "C=",C*10**12,"pF"##answer printed in the book is wrong.

C= 88.5 pF


## Ex 13.9 Pg 252¶

In [8]:
from __future__ import division
A=0.2#
C=0.428*10**-6#
e0=8.85*10**-12#
er=1200#
d=(e0*er*A)/C##ans printed in the book is wrong
print "d=",d*10**3,'mm'

d= 4.96261682243 mm