Question

Derive the formula of magnetic field due to a toroidal solenoid .​

Answer 1

Answer:

Magnetic Field of Toroid

For a solenoid of radius r = m with N = turns, the turn density is n=N/(2πr)= turns/m. B = Tesla = gauss. The Earth'smagnetic field is about half a gauss.

Explanation:

hope this helps ^_^

Answer 2

Answer:

Since the magnetic needle orients itself with its axis vertical, thus all the magnetic field must be in vertical direction and so horizontal component of earth's magnetic field must be zero.

Thus, angle of dip at that place is 90°