Answer:
a
The magnetic field strength is [tex]B = 2 \mu T[/tex]
Explanation:
From the question we are told that
The length line above the ground is [tex]R = 20m[/tex]
The current of the line is [tex]I = 200A[/tex]
The voltage of the line is [tex]V = 110kV[/tex]
Generally magnetic field strength is mathematically represented as
[tex]B = \frac{\mu_o I}{2 \pi R}[/tex]
Where [tex]\mu_0[/tex] is the permeability of free space [tex]= 4\pi * 10^{-7} N/A^2[/tex]
[tex]B = \frac{(4\pi * 10^{-7} N/A^2) *200}{2 \pi *20}[/tex]
[tex]= (2.0*10^{-7})[\frac{200}{20} ][/tex]
[tex]= 2*10^{-6}T[/tex]
[tex]= 2 \mu T[/tex]
Earths magnetic field is approximately given as [tex]50 \mu T[/tex]
So the percentage would be
[tex]= \frac{Magnetic \ Field \ Intensity \ Of \ Line}{Earth's \ Magnetic \ Field} * 100[/tex]
[tex]= \frac{2 \mu T }{50 \mu T } * 100[/tex]
[tex]=4[/tex]%
