Question

The magnetic induction at a point 1 cm from a thin, infinitely long, straight wire
carrying a current is 100μT. What is the current in the conductor?​

Answer 1

The magnetic induction/field at a point P at a distance r from a thin, infinitely long, straight wire  carrying a current I is given by:

                                    B = μ₀I/2πr

• Here it is given that r = 1 cm = 0.01 m

• μ₀ = 4π* 10^-7 Tm/A is magnetic permeability of free space
• B = 100μT is the magnetic field at point P

hence,                       I  = B*2πr/μ₀

                                  I = 5 A