sin∠OO 1k=L2L= 12…①
De: ∠OO 1k=π6
Then t = t0 = π 62 π t =112t ...
T=2πmqB…③
The solution is QM = π 6bt0; Therefore, B is correct;
From equation 2: T= 12t0, so a is wrong;
Because the initial velocity of particles is equal and the trajectory radius of all particles is equal, the particle with the longest trajectory has the largest central angle and the longest movement time in the magnetic field. If the initial velocity direction is opposite to the four vertices in the magnetic field, the arc length of the particles is not the longest, and the time is not the longest. So, C is right and D is wrong;
So: BC.