Bert Says That a Charged Particle in a Vacuum Can

question 50

Multiple Choice

Bert says that a charged particle in a vacuum can travel in a helix only if a uniform electric field and a uniform magnetic field are both present and both parallel to the axis of the helix. Stuart says that only a magnetic field with a component parallel to the axis of the helix is needed. Which one, if either, is correct, and why?

• A) Bert, because the charged particle's velocity can have a vertical component only if an electric field in the vertical direction is present.
• B) Stuart, because a component of velocity in the vertical direction is not changed by a vertical component of a magnetic field.
• C) Bert, because a component of velocity in the vertical direction is changed by a vertical component of a magnetic field.
• D) Stuart, because an electric field in the vertical direction would cause the particle to come to a complete stop.
• E) Neither, because particles cannot move in helical paths in the presence of magnetic and electric fields.

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Definitions:

Acceleration

The rate at which an object’s velocity changes with time, often measured in meters per second squared (m/s²).

Pressure

the feeling of psychological strain and stress, often arising from external sources that demand high performance or coping.

Vestibular System

The sensory system that provides the leading contribution to the sense of balance and spatial orientation for the purpose of coordinating movement with balance.

Gustatory System

The gustatory system is responsible for the sensation of taste, and it involves the taste buds on the tongue and other related neural structures.