A thin 2.82 m long copper rod in a uniform

Question

magnetic field has a mass of 44.2 g. When the
rod carries a current of 0.238 A, it floats in
the magnetic field.
The acceleration of gravity is 9.81 m/s2 .
What is the field strength of the magnetic
field?
Answer in units of T.

Answer 1

F = IBL
F= mg
mg = IBL
B = mg / IL

( (0.0442 kg)(9.8 m/s^2) / (0.238 A)(2.82 m) )

= 0.646 T