Question

An electrically charged particle enters into a uniform magnetic induction field in a direction perpendicular to the field with a velocity $ v $ . Then, it travels

• A. in a straight line without acceleration
• B. with force in the direction of the field
• C. in a circular path with a radius directly proportional to $ v^{2} $
• D. in a circular path with a radius directly proportional to its velocity

Answer 1

Answer: (D)

By motion of charged particles in uniform magnetic field

$r=\frac{m v}{q B}$
So, $r \propto v$
It travels in a circular path with a radius directly proportional to its velocity.