A proton is to circulate the earth along the equator with a speed of `1*0xx10^7ms^-1`. Find the minimum magnetic field which should be created at the equator for this purpose. The mass of proton `=1*7xx10^(-27)kg` and radius of earth `=6*37xx10^6m`.

Answer

`1*67xx10^-8T`

Explanation

`qv B=mv^2//r`
or `B=(mv)/(qr)=(1*7xx10^(-27)xx(1*0xx10^7))/((1*6xx10^(-19))xx(6*37xx10^6))`
`=1*67xx10^-8T`