Chapter 14: Inductance and Magnetic Fields

Example 14.1, Page 280

In [1]:
#Initialization
i=5                          #current in ampere
l=0.628                      #circumference


#Calculation
h=i/l                           #magnetic field strength

#Results
print'Magnetic Field Strength, H = %.2f A/m'%h

Magnetic Field Strength, H = 7.96 A/m

Example 14.2, Page 283

In [8]:
import math
#Initialization
i=6                          #current in ampere
n=500                       #turns
l=0.4                      #circumference
uo=4*math.pi*10**-7          #epsilon zero constant
a=300*10**-6                 #area

#Calculation
f=n*i                          #Magnetomotive Force
h=f/l                           #magnetic field strength
b=uo*h                          #magnetic induction
phi=b*a                          #flux

#Results
print'(a) Magnetomotive Force, H = %.2f ampere-turns'%f
print'(b) Magnetic Field Strength, H = %.2f A/m'%h
print'(c) B = %.2f mT'%(b*10**3)
print'(d) Toal Flux, phi = %.2f uWb'%(phi*10**6)

(a) Magnetomotive Force, H = 3000.00 ampere-turns
(b) Magnetic Field Strength, H = 7500.00 A/m
(c) B = 9.42 mT
(d) Toal Flux, phi = 2.83 uWb

Example 14.3, Page 285

In [11]:
#Initialization
l=10*10**-3                   #inductance in henry
di=3


#Calculation
v=l*di                            #voltage         

#Results
print'Voltage, V = %d mV'%(v*10**3)

Voltage, V = 30 mV

Example 14.4, Page 287

In [15]:
import math
#Initialization
n=400                        #turns
l=200*10**-3                 #circumference
uo=4*math.pi*10**-7          #epsilon zero constant
a=30*10**-6                 #area

#Calculation
L=(uo*a*n**2)/l                #Inductance in henry               

#Results
print'Inductance,L = %d uH'%(L*10**6)

Inductance,L = 30 uH

Example 14.5, Page 289

In [21]:
import math
#Initialization
l1=10                #Inductance in henry       
l2=20                #Inductance in henry       

#Calculation
ls=l1+l2                #Inductance in henry               
lp=((l1*l2)*(l1+l2)**-1)    #Inductance in henry       
#Results
print'(a) Inductance in series,L = %d uH'%ls
print'(b) Inductance in parallel,L = %.2f uH'%lp

(a) Inductance in series,L = 30 uH
(b) Inductance in parallel,L = 6.67 uH

Example 14.6, Page 293

In [26]:
import math
#Initialization
l=10**-2                #Inductance in henry       
i=5                  #current in ampere    

#Calculation
s=0.5*l*i**2           #stored energy

#Results
print'Stored Energy = %d mJ'%(s*10**3)

Stored Energy = 125 mJ
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