I couldnt type it out so here's a picture
Explanation:
It is given that,
Length of wire, l = 0.53 m
Current, I = 0.2 A
(1.) Approximate formula:
We need to find the magnitude of the magnetic field made by the current at a location 2.0 cm from the wire, r = 2 cm = 0.02 m
The formula for magnetic field at some distance from the wire is given by :


B = 0.000002 T

(2) Exact formula:


B = 0.00000199 T
or
B = 0.000002 T
Hence, this is the required solution.
Centripetal Force, F = mv²/r
Where m = mass in kg, v = velocity in m/s and r = radius of curvature in m.
Centripetal Force, F = 2000 * 25² / 80. Use your calculator.
F = 15 625 N.