Distinguishing Hall voltage from motional emf: is the Hall voltage simply the voltage created by a conductor moving through a magnetic field, or is it specifically a transverse voltage produced in a current-carrying conductor in a magnetic field due to carrier deflection?

Introduction / Context:
Both the Hall effect and motional emf involve magnetic fields and voltages, but they arise from different physical setups. This item tests whether the Hall voltage is correctly described.

Given Data / Assumptions:

• A Hall element with current driven through it.
• Magnetic field applied perpendicular to the current.
• No requirement for the bulk conductor to move relative to the field.

Concept / Approach:
The Hall voltage occurs because moving charge carriers (due to current) experience a Lorentz force in a magnetic field, which pushes them to one side of the conductor and creates a transverse voltage. In contrast, motional emf is generated when a conductor physically moves through a magnetic field lines (e = B * l * v) even without a prior current. Therefore, describing the Hall voltage as the voltage created by a conductor moving through a magnetic field conflates it with motional emf and is incorrect.

Step-by-Step Solution:

Verification / Alternative check:
Stationary Hall sensors on PCBs measure magnetic fields with no mechanical motion; this directly proves that motion of the bulk conductor is not required for V_H.

Why Other Options Are Wrong:
Correct: would wrongly equate Hall voltage with motional emf.

Restrictions to high fields or metals are irrelevant; Hall sensors often use semiconductors at modest fields.

Common Pitfalls:
Using motional emf formulas to predict Hall sensor outputs; ignoring the need for an applied current in Hall measurements.

Final Answer:
Incorrect