Answer:
8.8 mT
Step-by-step explanation:
Current through the conductor = 12.5 A
Magnetic force per unit length on the wire = 0.110 N/m
Recall that the magnetic force per unit length on a current carrying conductor is in a uniform magnetic field is

where B is the magnetic field magnitude
is the current in the conductor
α is the angle the conductor makes with the magnetic field ( since it is perpendicular in this case, α is 90°)
imputing values into the equation, we'll have
0.11 = 12.5 x B x sin 90°
but sin 90° = 1, therefore, we have
0.11 = 12.5B
B = 0.11/12 = 8.8 x 10^-3 T
or rather = 8.8 mT