Question

What is the value of `B` that can be set up at the equator to permit a proton of speed `10^7m//s` to circulate around the earth?
`[R=6.4xx10^6m,m_p=1.67xx10^-27kg]`

Answer 1

From the relation
`r=(mv)/(Bq)`
We have
`B=(mv)/(qr)`
Substituting the vaues we have
`B=((1.67xx10^-27)(10^7))/((1.6xx10^-19)(6.4xx10^6))`
`=1.6xx10^-8T`