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 $v^2$
• Correct answer
  D

  in a circular path with a radius directly proportional to its velocity

Solution

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.

Hence, the correct answer is option: 'D'.