In [6]:

```
import math
#Variable declaration
theta = 30 #Angle of radiation (degrees)
epsilon_0 = 8.854e-12 #Permittivity of free space (F/m)
I_dl = 10 #Current in length dl (A-m)
r = 100e3 #Distance of point from origin (m)
#Calculation
E_mag = (I_dl*math.sin(theta*math.pi/180))/(4*math.pi*epsilon_0)
#Magnitude of Electric field vector (V/m)
H_mag = (I_dl*math.sin(theta*math.pi/180))/(4)
#Magnitude of Magnetic field vector (T)
#Result
print "The magnitude of E vector is ", round(E_mag,-9), "V/m"
print "The magnitude of H vector is", round(H_mag, 3), "/pi T"
```

In [3]:

```
import math
#Variable declaration
v = 3e8 #Speed of light(m/s)
f = 10e6 #Frequency (Hz)
#Calculation
w = 2*math.pi*f #Angular frequency(rad/s)
r = v/w #Distance (m)
#Result
print "The distance for the specified condition is", round(r, 2), "m"
```

In [4]:

```
import math
#Variable declaration
c = 3e8 #Speed of light (m/s)
f = 3e9 #Frequency (Hz)
#Calculation
v = 0.6*c #60% of velocity of light (m/s)
w = 2*math.pi*f #Angular frequency (rad/s)
r = v/w #Distance (m)
#Result
print "The distance for the specified condition is", round(r,6), "m"
```

In [5]:

```
import math
#Variable declaration
dl = 1e-2 #Length of radiating element (m)
I_eff = 0.5 #Effective current (A)
f = 3e9 #Frequency (Hz)
c = 3e8 #Velocity of light (m/s)
#Calculation
w = 2*math.pi*f #Angular Frequency (rad/s)
P = 20*(w**2)*(I_eff**2)*(dl**2)/(c**2) #Radiated power (W)
#Result
print "The radiated power is", round(P, 2), "W"
#The final result is incorrect in the book because of the calculation mistake
```

In [6]:

```
#Variable declaration
L = 5 #Length of radiating element (m)
f1 = 30e3 #Frequency (Hz)
f2 = 30e6 #Frequency (Hz)
f3 = 15e6 #Frequency (Hz)
c = 3e8 #Velocity of light (m/s)
#Calculation
wave_lt1 = c/f1 #Wavelength (m)
wave_lt1 /= 10
R_r1 = 800*(L/wave_lt1)**2 #Radiation resistance (ohm)
wave_lt2 = c/f2 #Wavelength (m)
L = wave_lt2/2 #Effective length (m)
R_r2 = 200*(L/wave_lt2)**2 #Radiation resistance (ohm)
wave_lt3 = c/f3 #Wavelength (m)
L = wave_lt3/4 #Effective length (m)
R_r3 = 400*(L/wave_lt3)**2 #Radiation resistance (ohm)
#Result
print "The radiation resistance for f1 is", R_r1, "ohms"
print "The radiation resistance for f2 is", round(R_r2), "ohms"
print "The radiation resistance for f3 is", round(R_r3), "ohms"
```

In [8]:

```
import math
#Variable declaration
Im = 5 #Maximum current (A)
r = 1e3 #Distance (km)
eta = 120*math.pi #Intrinsic impedence (ohm)
theta = 60*math.pi/180 #Angle of radiation (radians)
#Calculation
sin2 = math.sin(theta)**2 #Sine squared theta (unitless)
P_av = (eta*(Im**2))/(8*(math.pi**2)*(r**2))
P_av = P_av*(math.cos(math.pi/2*math.cos(theta))**2)/(sin2)
#Average power (W)
#Result
print "The average power available at 1km distance is", round(P_av,9), "W"
```