Lorentz Force Overview
The term "Lorentz force" describes the combination of magnetic and electric forces that electromagnetic fields have on a point charge. Experts also refer to the Lorentz force as the electromagnetic force.
What is Lorentz Force?
The Lorentz force is the force exerted on a charged particle traveling through an electric and magnetic field. In the year 1895, Hendrik Lorentz developed the present Lorentz force formula. Lorentz's force explains how an electric and magnetic field interact with and affect a charged particle. It is the total electromagnetic force exerted on a charged particle. It is also referred to as electromagnetic force and is employed in electromagnetism.
Formula for Lorentz Force
The charged particle's Lorentz force formula is as follows-
The following is the Lorentz force formula for a continuous charge distribution-
dF = dq (E + v * B)
Where,
dF is a force on a small portion of the charge.
dq is a charge of some small piece.
The formula is as follows when a tiny portion of charge dispersion is split by the volume dV-
f = ρ (E + v * B)
Where,
f is force per unit volume.
ρ is charge density.
Finding the direction of the magnetic component of the force is simple with the use of the right-hand rule.
Importance of Lorentz Force
The physical significance of forces acting on charged particles as they travel through space with an electric and magnetic field is explained by Lorentz's force, which also explains the mathematical equations behind them. This is why the Lorentz force is significant.
Right-Hand Thumb Rule
- Since it is simple to visualize the direction as stated in the Lorentz force law, the right-hand rule is helpful in determining the magnetic force.
- It is clear from the preceding diagram that the magnetic force is orthogonal to the magnetic field and charge velocity.
Properties of Lorentz Force
The following are some of the properties of Lorentz Force-
Property 1
If the particle's direction of motion, electric and magnetic fields, and velocity are all parallel to one another and E and B are uniform,
Consequently,
F🇧= qv sin 0 = 0
As a result of the electric field's acceleration of the charge, the charge will move in a rectilinear fashion.
Property 2
If the magnetic and electric fields are parallel to one another and the particle's direction of motion is perpendicular to E and B,
F🇧≠ 0
As a result of the electric field's acceleration of the charge, the charge will move in a circular motion.
How to measure Lorentz Force?
There are two methods to measure the Lorentz force-
Method 1: A Moving Charge experiencing Lorentz Force in a B field
- When a charged particle moves through a magnetic field and crosses over field lines in the process, a Lorentz force is created. This force operates at a right angle to both the magnetic field, B, and the particle velocity, v. The direction of this force, depends on the magnetic field, the direction of the particle's motion, and the sign of the particle's charge in various circumstances. There are two methods to recall this force's direction, and both of them are variations on the "left-hand rule." These are rotated while being held at right angles to one another so that-
- The first finger is pointing in the magnetic field's direction.
- The Second finger is pointing in the direction of the Current
- The thumb is pointed in the direction that motion would tend if the magnetic force were the only force acting on the object.
- The left-hand rule can also be remembered by labeling your fingers with the letters "FBI" as an alternative. Consequently, "I" stands for the middle finger, "F" for the thumb, and "B" for the first finger. The relationship between the directions of the current I, force F, and magnetic field B might be shown by holding these three fingers at right angles to one another.
Read more about the Magnetic Effects of Electric Current.
Method 2: A Current-Carrying Wire in a Magnetic Field Experiences the Lorentz Force
Since the term "current" relates to the movement of charged particles, all of the charged particles in a wire carrying current would be subject to the Lorentz force. Therefore, one would need to calculate the total force acting on the charged particles in motion. This is due to the fact that the total force acting on the charged particles would equal the total force acting on the wire.
Read more about the Eddy Current.
What is Lorentz Law?
The combined force that an electric and magnetic field exert on a point charge is known as the Lorentz force law. The forces on moving charges caused by electromagnetic fields are referred to as Lorentz forces in the definition of the term.
Applications of Lorentz Force
The Lorentz force is used in the following situations-
- In order to divert electrons from traveling in a straight path and direct them to specific locations on the screen, a cathode ray tube television uses the Lorentz force theory.
- Lorentz force is used in cyclotrons and other particle accelerators.
- The graph used to determine the charged particle paths is created using the Lorentz force in a bubble chamber.
Points to Remember
- The combined force that a moving charge experiences in an electric and magnetic field is known as the Lorentz force.
- The force applied to a charged particle traveling through an electric field and a magnetic field is known as the Lorentz force.
- The formula for the Lorentz force is F = qE + qV x B.
- The Lorentz force formula for continuous charge distribution is dF- dq (E + vB).
- The Lorentz force is used in both the cyclotron and J.J. Thomson's experiment to estimate the particular charge of an electron.