Question

A horizontal overhead powerline is at a height of 4 m from the ground and carries a current of 100 a from east to west. The magnetic field directly below it on the ground is

Answer 1

Answer:

The answer will be 5×10−6 T southwards.

Explanation:

According to the problem the height of the horizontal power line is 4 m from the ground

The amount of the current passes through the power line is 100 a

Now let the magnetic field around a long current carrying wire is B

therefore, B =  μi/2πr  [where μ is the coefficient factor, i the current flowing, r is the height or radius]

Therefore,

B= 4π×10^(−7)×100/2π×4

  =5×10^(−6) T

Now from ampere's right and rule the direction of the magnetic field we can say that the direction  will be southwards