conducting wire

Question

 A thin conducting wire 0.853 m long has a mass of 60.4 g. The minimum current required in the wire to 
make it “float” in a magnetic field of 0.187 T is _.__ A

Answer 1

The force acting on the conducting wire F = m*g

Where m is the mass of conductor = 60.4 g = 0.0604 kg .

           g is acceleration due to gravity = 9.8 

F = 60.4*9.8 = 0.59192 N

The relation between force and magnetic field is F = I ℓ B

                                            ⇒ I = F / (ℓ B)

Where ℓ  is length of conductor = 0.853 m

        B is magnetic field = 0.187 T

I = 0.59192 / (0.853 * 0.187)

I = 0.59192 / 0.1595

I = 3.7108 A

So the minimum current required in the wire to make it “float” in a magnetic field is 3.7108 A