If a charged particle (+*) is projected with certain velocity parallel to the magnetic field, then it will

The force experienced by a charged particle moving in a magnetic field is governed by the Lorentz force equation, F = q(v × B), which can be expressed as F = qvB sin(θ). In this equation, θ represents the angle between the velocity vector (v) and the magnetic field vector (B). When a particle is projected parallel to the magnetic field, the angle θ is 0 degrees. Since sin(0°) is zero, the magnetic force acting on the particle becomes zero. Consequently, the particle experiences no magnetic deflection or acceleration that would change its path or speed. Therefore, the particle will continue its motion in a straight line with constant velocity, effectively continuing its motion without any change. Helical or circular paths only occur when there is a perpendicular component of velocity relative to the field.