Appendix B EM waves in conducting Medium

Example B.1 Page no 414

In [5]:
#Given
a=5.8*10**7                         #s/m
v=1                                 #MHz

#Calculation
import math
u=4*math.pi*10**-7
d=v/math.sqrt((math.pi*10**-6*u*a))

#Result
print"Skin depth is",round(d*10**-3,3),"mm"

Skin depth is 0.066 mm

Example B.2 Page no 414

In [27]:
#Given
a=2.56*10**-4
n=10.0**10
er=2.3
e0=8.85*10**-12
c=3*10**8

#Calculation
import math
v=a/(2*math.pi*n*er*e0)
V=c*math.sqrt(1/er)
B=(v*2*math.pi*n)/(2*v)

#Result
print"Phase velocity is", round(V*10**-8,2),"*10**8 m/s"
print"Magnitude of attenuation constant is",round(B*10**-10,2),"*10**-2"

Phase velocity is 1.98 *10**8 m/s
Magnitude of attenuation constant is 3.14 *10**-2

Example B.3 Page no 415

In [35]:
#Given
n=1.6*10**6                         #Hz
a=38.3*10**6                         #/sm

#Calculation
import math
d=1/(math.sqrt(math.pi*n*a*math.pi*4*10**-7))
v=2*math.pi*n*d

#Result
print"Skin depth is", round(d*10**6,1),"micro m"
print"Wave velocity is",round(v,0),"m/s"

Skin depth is 64.3 micro m
Wave velocity is 646.0 m/s