The force on a charge moving with velocity v in a magnetic field B is half of the maximum force when the angle between v and B is

Answer Details

When a charged particle moves in a magnetic field, it experiences a force called the magnetic force. This force is perpendicular to both the velocity of the particle and the magnetic field. The magnitude of the magnetic force is given by the equation F = qvBsinθ, where q is the charge of the particle, v is its velocity, B is the magnetic field, and θ is the angle between v and B.
The maximum force is obtained when the angle θ is 90 degrees, because sin(90) = 1, so the force is given by F_max = qvB.
According to the question, the force on the charge when θ is some other angle is half of the maximum force. So, we can write:
F = (1/2) F_max
F = (1/2) qvB
We can rearrange this equation to find the angle θ:
F = qvBsinθ = (1/2) qvB
sinθ = (1/2)
The only angle for which sinθ = (1/2) is 30 degrees. Therefore, the correct option is "30o".