Helmholtz galvanometer experiment 

Thanks a lot

​@@physicslabbymohanagarwal1793sir apne kaha ki magnetic meridian me rakhne per earth ke magnetic field ka koi effect nhi padega yani earth ka magnetic field neddle ke parallel ho ja rha hai jab current dene per tan theta kis magnetic field ka ratio hota hai...jabki current ka magnetic field bhi magnetic meridian ke parallel hai

@@KeshavKus Earth magnetic field must be perpendicular to the magnetic field of coil. Therefore we place it in magnetic meridian.

@@physicslabbymohanagarwal1793 yani sir tab magnetic needle bhi earth ke horizontal component ke perpendicular hoga...yani compass ka magnet aur needle dono 90 degree per honge.......

@@KeshavKus needle is always pointed to north- south directions. Coil magnetic field is perpendicular to it. Please read tangent law of magnetism.

No, but at 45°, I=K as tan45=1

​@@sanidhyapandey1it is not accurate explanation,since i = k tanø del i/i = 2 del ø/ sin2ø thus error will be minimum if sin2ø is max ie 1 so ø = pi/4 😊

At 45 degree horizontal component and vertical component becomes equal .now the variation of magne field finds in the region between 0 and 1. And things becomes normalize