A Bar (L = 80 Cm) Moves on Two Frictionless

Multiple Choice

A bar (L = 80 cm) moves on two frictionless rails, as shown, in a region where the magnetic field is uniform (B = 0.30 T) and into the paper. If v = 50 cm/s and R = 60 mΩ, what is the magnetic force on the moving bar?

A) 0.48 N to the right
B) 0.48 N to the left
C) 0.32 N to the left
D) 0.32 N to the right
E) None of the above