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3 years ago

8

Although the evidence is weak, there has been a concern in recent years over possible health effects from the magnetic fields ge

nerated by electric transmission lines. A typical high-voltage transmission line is 20 m above the ground and carries a 200 A current at a potential of 110 kV.
a. What is the magnetic field strength on the ground directly under such a transmission line?
b. What percentage is this of the earth's magnetic field of 50 ?T?

1 answer:

sergey [27]3 years ago

7 0

Answer:

a

The magnetic field strength is $B = 2 \mu T$

Explanation:

From the question we are told that

The length line above the ground is $R = 20m$

The current of the line is $I = 200A$

The voltage of the line is $V = 110kV$

Generally magnetic field strength is mathematically represented as

$B = \frac{\mu_o I}{2 \pi R}$

Where $\mu_0$ is the permeability of free space $= 4\pi * 10^{-7} N/A^2$

$B = \frac{(4\pi * 10^{-7} N/A^2) *200}{2 \pi *20}$

$= (2.0*10^{-7})[\frac{200}{20} ]$

$= 2*10^{-6}T$

$= 2 \mu T$

Earths magnetic field is approximately given as $50 \mu T$

So the percentage would be

$= \frac{Magnetic \ Field \ Intensity \ Of \ Line}{Earth's \ Magnetic \ Field} * 100$

$= \frac{2 \mu T }{50 \mu T } * 100$

$=4$ %

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