How much current is flowing in a wire 4.8 m long if the maximum force on it is 0.75 N when placed in a uniform 0.08 T field?  

Expert Answers
justaguide eNotes educator| Certified Educator

If a wire of length L carrying a current I lies in a magnetic field B, the force on the wire due to the interaction between magnetic fields is given by F = `I*LxxB` .

For a wire that is 4.8 m long, the maximum force on it due to a magnetic field is when the direction of the current and that of the magnetic field are perpendicular to each other.

When a 4.8 m long wire is placed in a 0.08 T field, the force acting on it is 0.750 N when a current X flows through it where:

X*4.8*0.08 = 0.75

=> X = 125/64

= X = 1.953215 A

The current flowing through the wire is 1.953215 A