Chapter 13: Capacitance and Electric Fields

Example 13.1, Page 264

In [5]:
#Initialization
c=10*10**-6                            #capacitance in Farad
v=10                                   #voltage

#Calculation
q=c*v                                   #charge in coulomb

#Results
print'Charge, q = %.1f uC'%(q*10**6)

Charge, q = 100.0 uC

Example 13.2, Page 264

In [9]:
#Initialization
l=25*10**-3            #length in meter
b=10*10**-3            #breadth in meter
d=7*10**-6            #distance between plates in meter
e=100                  #dielectric constant of material
e0=8.85*10**-12         #dielectric constant of air       

#Calculation
c=(e0*e*l*b)*d**-1        #Capacitance
#Results
print'Capacitance, C = %.1f nF'%(c*10**9)

Capacitance, C = 31.6 nF

Example 13.3, Page 268

In [18]:
#Initialization
v=100                          #voltage
d=10**-5                       #distance in meter

#Calculation
e=v*d**-1                      #Electric Field Strength

#Results
print'Electric Field Strength, E = %d ^7 V/m'%round(e*10**-6)

Electric Field Strength, E = 10 ^7 V/m

Example 13.4, Page 268

In [20]:
#Initialization
q=15*10**-6                     #charge in coulomb
a=200*10**-6                    #area

#Calculation
d=q/a                           #electric flux density

#Results
print'D = %d mC/m^2'%(d*10**3)

D = 75 mC/m^2

Example 13.5, Page 270

In [21]:
#Initialization
C1=10*10**-6                     #capacitance in Farad
C2=25*10**-6                     #capacitance in Farad

#Calculation
C=C1+C2                     #capacitance in Farad

#Results
print'C = %d uF'%(C*10**6)

C = 35 uF

Example 13.6, Page 271

In [23]:
#Initialization
C1=10*10**-6                     #capacitance in Farad
C2=25*10**-6                     #capacitance in Farad

#Calculation
C=(C1*C2)/(C1+C2)                     #capacitance in Farad

#Results
print'C = %.2f uF'%(C*10**6)

C = 7.14 uF

Example 13.7, Page 275

In [35]:
#Initialization
C1=10*10**-6                     #capacitance in Farad
V=100                            #voltage

#Calculation
E=(0.5)*(C1*V**2)              #Energy stored

#Results
print'E = %.1f mJ'%(E*10**3)

E = 50.0 mJ
In [ ]: