Direction of Force and Magnetic Field
Understanding the relationship between the direction of force and the direction of the magnetic field is crucial in the study of electromagnetism. The correct answer to the question is option 'C', which is perpendicular. Let's delve into the details to understand why this is the case.

Force on a Charged Particle in a Magnetic Field
When a charged particle moves through a magnetic field, it experiences a force known as the Lorentz force. This force is perpendicular to both the direction of the magnetic field and the direction of the particle's velocity. The magnitude of this 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 strength, and θ is the angle between the velocity and the magnetic field.

Direction of the Force
The direction of the force on a charged particle in a magnetic field is determined by the right-hand rule. If you point your thumb in the direction of the velocity of the charged particle and your fingers in the direction of the magnetic field, the force will be perpendicular to both, in a direction determined by the palm of your hand.

Perpendicular Relationship
Therefore, the force experienced by a charged particle in a magnetic field is always perpendicular to the direction of the magnetic field. This relationship is a fundamental principle in electromagnetism and is crucial in various applications, such as particle accelerators, magnetic resonance imaging (MRI), and electric motors.
In conclusion, the direction of the force on a charged particle in a magnetic field is always perpendicular to the direction of the magnetic field. Understanding this relationship is essential in the field of electrical engineering and electromagnetic theory.