The magnetic field of the

Question

• Suppose that the magnetic field of the Earth were due to a single current moving in a circle of radius 2960 km through the Earth's molten core. The strength of the Earth's magnetic field on the surface near a magnetic pole is about 6. *10^-5 T. About how large a current would be required to produce such a field? (The radius of the Earth is 6.39 *10³ km.)

• A square loop, with sides of length L, carries current i. Find the magnitude of the magnetic field from the loop at the center of the loop, as a function of i and L. (Use any variable or symbol stated above along with the following as necessary: μ₀.)

• The figure below shows a Helmholtz coil used to generate uniform magnetic fields. Suppose the Helmholtz coil consists of two sets of coaxial wire loops with 13 turns of radius R = 71.0 cm, which are separated by R, and each coil carries a current of 0.134 A flowing in the same direction. Calculate the magnitude and the direction of magnetic field in the center between the coils.

• What is the magnitude of the magnetic field inside a long, straight tungsten wire of circular cross section with diameter 3.6 mm and carrying a current of 2.7 A, at a distance of 0.5 mm from its central axis? (The magnetic suspect