Question

Motion of a particle in a magnetic field related question

Answer 1

@Mashy @shubhamsrg

Answer 2

one simply does not tag me in a physics question!

Answer 3

ok :/

Answer 4

Anyways, I;ll try to attempt :

B due to moving charge = u0/4pi * q (v x r)/|r|^3 , B,v and r are vectors here.
A will record 0 magnetic field when v and r are parallel or anti parallel .
That'll be when :

Now easily we can find that angle ,
that'll be pi/3

now, pi/3 = w t

so w = pi/3t

^_^