A horizontal overhead power line carries a current of 90 A in east towest direction. What is the magnitude and direction of the magneticfield due to the current 1.5 m below the line?
Given: The current carried over power line is 90 A , the distance of the point from the line is 1.5 m .
Magnetic field at a point due to power line is given as,
B = μ 0 2 I 4 π r
where, the permeability of free space is μ 0 , current carried by the power line is I , and the distance of the point is r .
By substituting the given values in the above equation, we get,
B = 4 π × 10 − 7 × 2 × 90 4 π × 1.5 = 1.2 × 10 − 5 T
Therefore, the magnetic field at a point due to power line is 1.2 × 10 − 5 T . From right hand thumb's rule, the direction of the magnetic field at the observation point is towards the south.
Given: The current carried over power line is
Magnetic field at a point due to power line is given as,
where, the permeability of free space is
By substituting the given values in the above equation, we get,
Therefore, the magnetic field at a point due to power line is
