There is an electric current in a wire of mass per unit length 40 g m⁻¹. The wire is placed in a magnetic field of strength 0.50 T and the current is gradually increased until the wire just lifts off the ground.
What is the value of the current when this happens?
A. 0.080 A
B. 0.20 A
C. 0.78 A
D. 780 A