Magnetic field
Objective
Determination of the horizontal component of the earth's magnetic field and magnetic induction .

Theory
The field component at the center if a coil of n turns carrying a current I is given by
Hc =ni/2a (A/m)
I =current (ampere)
N=number of turns .
a= radius of coil (in meter)




Where θ is the angle of deflection of the compass needle.


tanθ avgθ 2θ 1θ I (A)





tanθ

slope= n/2aHe

I(A)

He=n/2aslope
B=μ0 H
Where μ0 is the permeability of free space = 10^-7×4π