1) You plan to build a large, cheap cyclotron using the Earth's magnetic fields(1x10^-4 T) and orbiting just above the Earth's atmosphere (radius 5.7 x10 ^6 m) What energy, in volts, should protons be given to just circle the earth? q= 1.6 x10^-19 C, m= 1.67x10^-27


2) Starting from Ampere's Law that the integal of B DOT dl around a closed path = (mu zero) i Show that the magnetic field B is uniform inside an infinite solonoid and is equal to (mu zero) n i, where the solonoid has n turns per meter each carring a current i.
pl help

For prob 1 have used the formula,

Kinetic energy of orbiting proton
= B^2q^2r^2/2m joules and then converted it into MeV. Am i right?
Prob 2 is a bookwork.