An electron and a proton are moving on straight parallel paths with same velocity. They enter a semi infinite region of uniform magnetic field perpendicular to the velocity. Which of the following statement(s) is /are true?

Options

A. they will never come out of the magnetic field region
B. they will come out travelling along parallel paths
C. they will come out at the same time
D. none of the above

Answer

B

Explanation

Radius `r=(mv)/(Bq)`or `r prop m`

`therefore` we have `r_(e ) lt r_(p)` as `m_(e ) lt m_(p)`
further time period `T=(2pi m)/(Bq)` or `T prop m rarr T_(e )lt T_(p)`
`t_(e )=(T_(e ))/(2)` and `t_(p)=(T_(p))/(2)`
l`t_(e ) lt t_(p)`