Question

Hall Effect Sensor Questions

Q1: Inside the Sensor, what happens when you reverse magnet 180 degrees?Explain why

Q2: How does a Hall Effect Sensor Work?

Answer 1

2. Let us first understand in simple terms what is Hall effect.

When a magnetic field is applied at right angle to a conductor carrying current, a voltage is developed across the conductor in a direction perpendicular to both , the current and the magnetic field. This is called Hall voltage.

When an electric current flows through any material, the electrons within the current naturally move in a straight line, with the electricity creating its own magnetic field as it charges.

If the electrically-charged material is placed between the poles of a permanent magnet, instead of moving in a straight line, the electrons will instead deviate into a curved path as they move through the material. This happens because their own magnetic field is reacting to the contrasting field of the permanent magnet.

As a result of this new curved movement, more electrons are then present at one side of the electrically-charged material. Through this, a potential difference (or voltage) will then appear across the material at right angles to the magnetic field, from both the permanent magnet and the flow of the electric current. Hence the corresponding Hall voltage developed is proportional to the insensity of magnetic field applied.

1.Now what will happen if the magnet polarity is reversed?

When the polarity of the magnet is reverses by rotating it 180 degrees, the Hall coefficient/constant is a constant for the given conductor. On reversing the direction of magnetic field by reversal of magnet, polarity of the Hall voltage developed reverses with reversal, but the Hall coefficient does not change sign.