Question

What minimum strength of magnetic field is required to balance the gravitational force on a proton moving at speed 7 ✕ 106 m/s?

Answer 1

If magnetic force on proton is balanced by its weight then we can write the equation

`F_(mag) = mg`

`qvB = mg`

now magnetic field is given by

`B = (mg)/(qv)`

here

`m = 1.6 * 10^(-27) kg`

`q = 1.6 * 10^(-19)C`

`v = 7 * 10^6 m/s`

`B = (1.6*10^(-27)* 9.8)/(1.6 * 10^(-19)*7 * 10^6)`

`B = 1.4 * 10^(-14) T`