Let B = B i
Fa = -(0.138 N) k
Fb = (0.138 N) k
Fc = 0
Each of the forces Fa and Fa contribute a torque of 0.045 N-m up.
The magnetic dipole moment is 1.2 A-m2.
Expression for torque is (i L2 B)/(4 pi N).
a) voltmeter: 542 ohm in series
b) ammeter: 2.52 ohm in parallel
Least current required is 2.45 A.