Answer:

Given, mass of the wire =200g=0.2kg

Length of the wire =15m

Current i=2A

Magnetic field B=?

The force acting on the current carrying wire in uniform magnetic field

F=Bilsinθ

F=Bil (∵θ=90⁰ )

Weight of the wire w=mg=0.2×9.8N

In the position of suspension

Bil=mg

B= mg/il = 0.2×9.8/2×15

=0.65T