Question

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

• 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 different times
• D. They will come out at the same time

Answer 1

Answer: (B), (C)

They will come out at different times



$\frac{m{v}^2}{r}=qvB$

$\Rightarrow r=\frac{mv}{qB}$

$m_e<m_p$

$\Rightarrow r_e<r_p$

$\Rightarrow t_e<t_p$