Answer:
The magnetic force is 0.3 N.
Explanation:
Given that,
Current in an unusual lightning strike, I = -400 A
The Earth’s magnetic field at that location is parallel to the ground and has a magnitude of 30 μT,
We need to find the force exerted by the Earth’s magnetic field on the 25 m-long current.
The magnetic force is given by :
So, the magnetic force is 0.3 N.