The radius of the earth is 6.4 x 106 m. The specific charge of the proton is 9.6 x 107 Ckg-1. What should be the value of the minimum magnetic field at the equator of the earth such that a proton moving with velocity 1.92 x 107 ms-1 may revolve around the earth?
1
1.57 x 10-8 T
2
3.12 x 10-8 T
3
5.36 x10-6 T
4
7.83 x 10-6 T